Updated after squad lists to UEFA (Andre Ayew may join PSG and Kolo Toure Galasaray + Arsenal has yet to release B list). Major changes in some clubs, as they didn't add the African players to their lists (like CFR Cluj or Anderlecht):

POT 1:
AC MILAN (5): Sulley Muntari, Kevin Prince Boateng, Kingsley Boateng (all Ghana), Kevin Constant (Guinea), Djamel Mesbah (Algeria)
ARSENAL FC (4): Gervinho, Serge Gnabry (both Cote d'Ivoire), Emmanuel Frimpong (Ghana), Marouane Chamakh (Morocco)
CHELSEA (4): Victor Moses, Mikel Obi (both Nigeria), Aziz Deen-Conteh (Sierra Leone), Daniel Pappoe (Ghana)
FC PORTO (3): Cadu (Angola), Christian Atsu (Ghana), Abdoulaye Ba (Senegal)
REAL MADRID (1): Michael Essien (Ghana)
BARCELONA (1): Alex Song (Cameroon)
MANCHESTER UNITED (0)
BAYERN MUNICH (0)
Last season: 14
This season: 18

POT 2:
DYNAMO KIEV (4): Aide Ideye Brown, Taye Taiwo, Lukman Haruna, Yussuf Ayila (all Nigeria)
BRAGA (4): Zé Luís (Cape Verde), Éder (Guinea Bissau), Djamal (Libya), Uwa Elderson Echiéjilé (Nigeria),
MANCHESTER CITY (2): Yaya Toure, Abdul Razak (all Cote d'Ivoire)
SCHALKE 04 (2): Joel Matip (Cameroon), Chinedu Obasi (Nigeria)
VALENCIA FC (1): Sofiane Feghouli (Algeria)
ZENIT ST PETERSBURG (0)
BENFICA (0)
SZACHTAR DONETSK (0)
Last season: 17
This season: 13

POT 3:
LILLE (6): Aurélien Chedjou (Cameroon), Idrissa Gana Gueye (Senegal), Barel Mouko (Congo), Adama Soumaoro, Salomon Kalou (both Cote d'Ivoire), Ryan Mendes (Cape Verde)
FSC ANDERLECHT (3): Mbenza Bedi, Dieumerci Mbokani (both DRCongo), Cheikhou Kouyaté (Senegal)
OLYMPIAKOS FC (3): Rafik Djebbour, Djamel Abdoun (both Algeria), Drissa Diakite (Mali)
GALATASARAY (3): Emmanuel Eboué (Cote d'Ivoire), Dany Nounkeu (Cameroon), Nordin Amrabat (Morocco)
AJAX AMSTERDAM (2): Eyong Enoh (Cameroon), Thulani Serero (South Africa)
PARIS SAINT GERMIAN (1): Mohamed Sissoko (Mali)
JUVENTUS (1): Kwadwo Asamoah (Ghana)
SPARTAK MOSKVA (1): Emmanuel Emenike (Nigeria)
Last season: 19
This season: 20

POT 4:
MONTPELLIER (7): Henri Bedimo (Cameroon), John Utaka (Nigeria), Souleymane Camara (Senegal), Karim Aït-Fana, Younès Belhanda, Abdelhamid El Kaoutari (all Morocco), Jamel Saihi (Tunisia)
CELTIC FC (4): Victor Wanyama (Kenya), Efe Ambrose, Rabiu Ibrahim (both Nigeria), Lassad Nouioui (Tunisia)
FC NORDSJAELLAND (2): Enoch Adu, Kamal Issah (both Ghana)
MALAGA (2): Fabrice Olinga, Carlos Kameni (both Cameroon)
CFR CLUJ (1): Modou Sougou (Senegal)
BORUSSIA DORTMUND (0)
BATE BORISOV (0)
DINAMO ZAGREB (0)
Last season: 8
This season: 15

DIVISION BY COUNTRY:
12 PLAYERS: NIGERIA
10 PLAYERS: GHANA
8 PLAYERS: CAMEROON
7 PLAYERS: COTE D'IVOIRE
5 PLAYERS: SENEGAL, MOROCCO
4 PLAYERS: ALGERIA
2 PLAYERS: TUNISIA, DRCONGO, CAPE VERDE, MALI
1 PLAYER: SIERRA LEONA, ANGOLA, GUINEA, GUINEA BISSAU, LIBYA, CONGO, SOUTH AFRICA, KENYA

This year 67 players from 19 countries (last year 59 from 17 - a 14% increase).

The 4 dominant forces: Nigeria, Ghana, Cameroon, Cote d'Ivoire

8 clubs have no African players (11 last season)

DIVISION BY COUNTRY OF CLUB:
France: 14
England: 10
Portugal: 7
Italy: 6
Spain: 5
Ukraine, Scotland: 4
Belgium, Turkey, Greece: 3
Germany, Holland, Denmark: 2
Russia, Romania: 1

You are good

Africans left in the knockout phase after the transfer window.

AC MILAN (5): Sulley Muntari, Kevin Prince Boateng, Kingsley Boateng (all Ghana), Kevin Constant (Guinea), Bakaye Traoré (Mali)
GALATASARAY (4): Emmanuel Eboué (Cote d'Ivoire), Dany Nounkeu (Cameroon), Nordin Amrabat (Morocco), Didier Drogba (Cote d'Ivoire)
CELTIC FC (3): Victor Wanyama (Kenya), Efe Ambrose (Nigeria), Lassad Nouioui (Tunisia)
FC PORTO (3): Cadu (Angola), Christian Atsu (Ghana), Abdoulaye Ba (Senegal)
ARSENAL FC (3): Gervinho, Serge Gnabry (both Cote d'Ivoire). Marouane Chamakh (Morocco)
SCHALKE 04 (2): Joel Matip (Cameroon), Chinedu Obasi (Nigeria)
MALAGA (2): Fabrice Olinga, Carlos Kameni (both Cameroon)
JUVENTUS (1): Kwadwo Asamoah (Ghana)
REAL MADRID (1): Michael Essien (Ghana)
BARCELONA (1): Alex Song (Cameroon)
VALENCIA FC (1): Sofiane Feghouli (Algeria)
PARIS SAINT GERMIAN (1): Siaka Tiene (Cote d'Ivoire)
BAYERN MUNICH (0)
SZACHTAR DONETSK (0)
BORUSSIA DORTMUND (0)
MANCHESTER UNITED (0)

DIVISION BY COUNTRY:
6 PLAYERS: GHANA
5 PLAYERS: CAMEROON, COTE D'IVOIRE
2 PLAYERS: NIGERIA
1 PLAYER: SENEGAL, MOROCCO, ALGERIA, TUNISIA, MALI, ANGOLA, GUINEA, KENYA

That means 26 players left from 12 countries. Hardest hit is Nigeria who lost 10 players after the group phase.

The 3 dominant forces remaining: Ghana, Cameroon, Cote d'Ivoire

4 clubs have no African players (25%)

DIVISION BY COUNTRY OF CLUB:
Italy: 6
Spain: 5
Turkey: 4
Portugal: 3
Scotland: 3
Germany: 2
England: 2
France: 1

EUROPA LEAGUE STATS (last 16):
Africans left in the knockout phase after the transfer window.

FC BASEL (6): Serey Die, Gilles Yapi Yapo (both Cote d'Ivoire), Jacques Zaou (Cameroon), Mohamed Salah, Mohamed Elneny (Egypt), Cabral (Cape Verde)
FC GIRONDIS DE BORDEUAX (6): Abdou Traoré, Cheick Diabaté (both Mali), Ludovic Sané (Senegal), Landry N'Guémo (Cameroon), André Poko (Gabon), Fahid Ben Khalfallah (Tunisia)
NEWCASTLE FC (5): Sammy Ameobi, Shola Ameobi (both Nigeria), Papiss Cisse (Senegal), Gaël Bigirimana (Rwanda), Cheick Tioté (Cote d'Ivoire)
FC ANZHI MAKHACHKALA (4): Samuel Eto'o (Cameroon), Lacina Traore (Cote d'Ivoire), Mehdi Carcela-Gonzalez, Mbark Boussoufa (both Morocco)
VFB STUTTGART (3): Mamadou Bah, Ibrahima Traore (both Guinea), Arthur Boka (Cote d'Ivoire)
LEVANTE (3): Nabil El Zhar (Morocco), Obafemi Martins (Nigeria), Pape Diop (Senegal)
FENERBAHCE FC (3): Joseph Yobo (Cameroon), Moussa Sow (Senegal), Pierre Webo (Cameroon)
CHELSEA FC (3): Obi Mikel, Victor Moses (both Nigeria), Demba Ba (Senegal)
INTER MILAN (2): Joel Obi (Nigeria), Ibrahima M'baye (Senegal)
TOTTENHAM FC (2): Emmanuel Adebayor (Togo), Benoit Assou-Ekotto (Cameroon)
LAZIO (1): Ogenyi Onazi (Nigeria)
FC RUBIN KAZAN, FC ZENIT SAINT PETERSBURG, FC STEAUA BUCARESTI, BENFICA, FC VIKTORIA PLZEN (0)

DIVISION BY COUNTRY:
8 PLAYERS: NIGERIA
6 PLAYERS: SENEGAL
5 PLAYERS: CAMEROON, COTE D'IVOIRE
3 PLAYERS: MOROCCO
2 PLAYERS: EGYPT, MALI, GUINEA
1 PLAYER: CAPE VERDE, GABON, TUNISIA, RWANDA, TOGO

That means 38 players left from 13 countries.
Surprisingly enough the most prominent national side in the Champions League Ghana have no players in the Europa League.

The 4 dominant forces remaining: Nigeria, Senegal, Cameroon, Cote d'Ivoire

5 clubs have no African players (31,25%)

DIVISION BY COUNTRY OF CLUB:
England: 10
Switzerland: 6
France: 6
Russia: 4
Germany: 3
Spain: 3
Italy: 3
Turkey: 3

marutimon: Africans left in the knockout phase after the transfer window.

AC MILAN (5): Sulley Muntari, Kevin Prince Boateng, Kingsley Boateng (all Ghana), Kevin Constant (Guinea), Bakaye Traoré (Mali)
GALATASARAY (4): Emmanuel Eboué (Cote d'Ivoire), Dany Nounkeu (Cameroon), Nordin Amrabat (Morocco), Didier Drogba (Cote d'Ivoire)
CELTIC FC (3): Victor Wanyama (Kenya), Efe Ambrose (Nigeria), Lassad Nouioui (Tunisia)
FC PORTO (3): Cadu (Angola), Christian Atsu (Ghana), Abdoulaye Ba (Senegal)
ARSENAL FC (3): Gervinho, Serge Gnabry (both Cote d'Ivoire). Marouane Chamakh (Morocco)
SCHALKE 04 (2): Joel Matip (Cameroon), Chinedu Obasi (Nigeria)
MALAGA (2): Fabrice Olinga, Carlos Kameni (both Cameroon)
JUVENTUS (1): Kwadwo Asamoah (Ghana)
REAL MADRID (1): Michael Essien (Ghana)
BARCELONA (1): Alex Song (Cameroon)
VALENCIA FC (1): Sofiane Feghouli (Algeria)
PARIS SAINT GERMIAN (1): Siaka Tiene (Cote d'Ivoire)
BAYERN MUNICH (0)
SZACHTAR DONETSK (0)
BORUSSIA DORTMUND (0)
MANCHESTER UNITED (0)

DIVISION BY COUNTRY:
6 PLAYERS: GHANA
5 PLAYERS: CAMEROON, COTE D'IVOIRE
2 PLAYERS: NIGERIA
1 PLAYER: SENEGAL, MOROCCO, ALGERIA, TUNISIA, MALI, ANGOLA, GUINEA, KENYA

That means 26 players left from 12 countries. Hardest hit is Nigeria who lost 10 players after the group phase.

The 3 dominant forces remaining: Ghana, Cameroon, Cote d'Ivoire

4 clubs have no African players (25%)

DIVISION BY COUNTRY OF CLUB:
Italy: 6
Spain: 5
Turkey: 4
Portugal: 3
Scotland: 3
Germany: 2
England: 2
France: 1

thanks for this stat.

CL and Europa League match-ups:

CHAMPIONS LEAGUE
Galatasaray (4 Africans) vs Schalke 04 (2 Africans)
Celtic (3) vs Juventus (1)
Arsenal (3) vs Bayern (0)
Shakthar Donetsk (0) vs Borussia Dortmund (0)
Milan (5) vs Barcelona (1)
Real Madrid (1) vs Manchester United (0)
Valencia (1) vs Paris Saint-Germain (1)
Porto (3) vs Málaga (2)

So 13-15 Africans should survive to the 1/4 final.

EUROPA LEAGUE
Viktoria Plzeň (0) vs Fenerbahçe (3)
Benfica (0) vs Bordeaux (6)
Anzhi Makhachkala (4) vs Newcastle United (5)
Stuttgart (3) vs Lazio (1)
Tottenham Hotspur (2) vs Internazionale (2)
Levante (3) vs Rubin Kazan (0)
Basel (6) vs Zenit St. Petersburg (0)
Steaua București (0) vs Chelsea (3)

Africans left in 1/4 finals of both competitions:

GALATASARAY (4): Emmanuel Eboué (Cote d'Ivoire), Dany Nounkeu (Cameroon), Nordin Amrabat (Morocco), Didier Drogba (Cote d'Ivoire)
MALAGA (2): Fabrice Olinga, Carlos Kameni (both Cameroon)
JUVENTUS (1): Kwadwo Asamoah (Ghana)
REAL MADRID (1): Michael Essien (Ghana)
BARCELONA (1): Alex Song (Cameroon)
PARIS SAINT GERMIAN (1): Siaka Tiene (Cote d'Ivoire)
BAYERN MUNICH (0)
BORUSSIA DORTMUND (0)

DIVISION BY COUNTRY:
4 PLAYERS: CAMEROON
3 PLAYERS: COTE D'IVOIRE
2 PLAYERS: GHANA
1 PLAYER: MOROCCO

That means 10 players left from 4 countries.

The 3 dominant forces remaining: Ghana, Cameroon, Cote d'Ivoire

2 clubs have no African players (25%)

DIVISION BY COUNTRY OF CLUB:
Turkey: 4
Spain: 4
France, Italy: 1

----------------------------------------------

EUROPA LEAGUE STATS (last 16):
Africans left in the knockout phase after the transfer window.

FC BASEL (6): Serey Die, Gilles Yapi Yapo (both Cote d'Ivoire), Jacques Zaou (Cameroon), Mohamed Salah, Mohamed Elneny (Egypt), Cabral (Cape Verde)
NEWCASTLE FC (5): Sammy Ameobi, Shola Ameobi (both Nigeria), Papiss Cisse (Senegal), Gaël Bigirimana (Rwanda), Cheick Tioté (Cote d'Ivoire)
FENERBAHCE FC (3): Joseph Yobo (Cameroon), Moussa Sow (Senegal), Pierre Webo (Cameroon)
CHELSEA FC (3): Obi Mikel, Victor Moses (both Nigeria), Demba Ba (Senegal)
TOTTENHAM FC (2): Emmanuel Adebayor (Togo), Benoit Assou-Ekotto (Cameroon)
LAZIO (1): Ogenyi Onazi (Nigeria)
FC RUBIN KAZAN, BENFICA (0)

DIVISION BY COUNTRY:
5 PLAYERS: NIGERIA
4 PLAYERS: CAMEROON
3 PLAYERS: SENEGAL, COTE D'IVOIRE
2 PLAYERS: EGYPT
1 PLAYER: CAPE VERDE, RWANDA, TOGO

That means 20 players left from 8 countries.

The 4 dominant forces remaining: Nigeria, Senegal, Cameroon, Cote d'Ivoire

2 clubs have no African players (25%)

DIVISION BY COUNTRY OF CLUB:
England: 10
Switzerland: 6
Turkey: 3
Italy: 1