The Chilean is a major doubt for the Aston Villa tie.
Arsenal's Danny Welbeck could miss the weekend's game with Manchester City.
Arsenal forward Danny Welbeck wants his club to put pressure on their main rivals.
The former Manchester United striker scored against West Ham United in the 2-1 win at the Boleyn Ground, but will hope to find the net more often.
Danny Welbeck has a chance to stake his claim for a central spot once again for Arsenal.
We take a look back at Danny Welbeck's 2014, where he moved from Manchester United to Arsenal.
Arsenal’s Danny Welbeck was out of sorts in the 2-2 draw at Liverpool in the Premier League on Sunday.
Arsenal striker Olivier Giroud netted twice during the Gunners’ 4-1 thrashing of Newcastle United.
If you were Arsene Wenger and had to pick the Gunners' best starting XI with everyone fit...
Alexis Sanchez and Danny Welbeck were Arsenal's two most high profile signings from the summer, and have got the blessing of Per Mertesacker.