The former Liverpool star was replaced by Pedro Rodriguez despite scoring a goal.
The Uruguay international has adapted well to the demands of the Nou Camp.
Some reports suggested the striker attempted to bite Martin Demichelis into the 92nd minute of the game.
United are a shambles and must rue their refusal to hire Jose Mourinho.
City boss says Hart's stop to deny Lionel Messi keeps his side in contention
The Uruguayan international has scored four La Liga goals since his summer move from Anfield.
Allen believes the new 3-5-2 system employed by Brendan Rodgers has made them better than they were last season.
Liverpool also wanted Chilean international to replace Luis Suarez
Coutinho signed a new five-and-a-half year deal with Liverpool last week.
Barcelona will take on Atletico Madrid in the quarter-finals of the Copa del Rey at the Vicente Calderon . Find out where to watch live in the UK.
The 20-year-old is working on his finishing ability after a series of missed chances this season.
Brendan Rodgers is happy with the squad at his disposal until the end of the current campaign.
Barcelona striker Luis Suarez believes his former club Liverpool will still be able to attract top players.
Liverpool are considering a move in signing Villarreal forward Luciano Vietto in January.
Wenger also convinced Sanchez to leave Barcelona and avoid Liverpool with Champions League promise.
Mascherano joined the Catalans in summer 2010 for around £20m.
Six footballers named for first ever Fallan d'Floor award for most theatrical dive.
Liverpool have reportedly sent scouts to watch Jaime Baez, who is dubbed as the "New Luis Suarez".
Real Madrid and Bayern Munich are reportedly monitoring the situation.
The Uruguay international is yet to score a La Liga goal after seven appearances.
The Uruguayan international had an incident with Thiago Silva during the Champions League win.
The former Liverpool star backs Messi to win the Ballon D'or.