Arsene Wenger has revealed that Cesc Fabregas is a major doubt for Tuesday's Champions League clash with FC Porto after suffering a recurrence of a hamstring injury against Burnley.
Skipper Fabregas scored the opening goal in a 3-1 success at the Emirates Stadium which maintained his side's push for the Premier League title.
However, the midfield playmaker was forced off with a recurrence of a hamstring injury just minutes later in what could prove to be a major blow to the north London club's hopes of winning silverware this season.
Fabregas missed three weeks of the season in January after suffering a similar complaint and the Gunners take on FC Porto in midweek trailing 2-1 from last month's first leg of their last 16 tie in Portugal.
"He has a hamstring problem and we don't know how big the damage is yet because it is too early. We'll see on Sunday or Monday," explained Wenger.
"We have to make a late decision over whether he plays on Tuesday, certainly. It is the same hamstring (he hurt against Aston Villa earlier in the season)."
Meanwhile, Wenger believes his side's consistency in recent weeks marks them out as serious title contenders.
"It is down to our consistency. If we win our games, we will be there, that is for sure," continued Wenger. "But you have experienced again today that every game demands full focus and commitment.
"When you play against teams who fight not to go down, they will fight until the last minute. Next week we play at Hull and expect exactly the same type of game."