The Chilean striker made a much anticipated return in Sunday's 1-0 defeat.
Olivier Giroud made way for defender Gabriel Paulista after Per Mertesacker’s red card.
Arsenal lost to Chelsea in the Premier League on Sunday evening.
It's between Arsenal, Leicester City, Manchester City and Tottenham Hotspur.
West Ham are working on a complicated deal for a striker, according to David Sullivan.
Mauricio Pochettino isn't interested in what Brendan Rodgers has to say about Dele Alli.
Arsenal legend Thierry Henry has Tottenham Hotspur down as title contenders.
Sunderland's Will Buckley starred on his first Birmingham City start - a far cry from his poor Leeds United loan.
The 33-year-old took to social media after the Gunners' 1-0 loss to the Blues.
Marcus Bean has hailed QPR's signing of goalkeeper Matt Ingram.