By Arsenal correspondent Tony Hughes

Arsenal fear Aaron Ramsey could be ruled out for the rest of the season with the thigh injury he sustained on Tuesday night, Football Insider sources understand.

The Gunners are braced for shattering news as they await the results of the scan taken on Ramsey’s right thigh.

Arsene Wenger and his staff do not expect the midfield lynchpin to be involved in Sunday’s FA Cup quarter-final clash against Watford.

They fear he will be out for an extended period of at least a month and possibly even until the end of the season in what would be a devastating blow to their hopes of lifting some silverware this season.

Wenger’s team host Watford in Sunday’s quarter-final before travelling to Barcelona in the second leg of a last-16 Champions League tie and then a trip to Everton in the Premier League title race.

Ramsey, Per Mertesacker and Gabriel were all forced off during the 4-0 win at the KC Stadium, and substitute Nacho Monreal was limping heavily after the game.

They join Petr Cech and Laurent Koscielny on the sidelines as well as long-term absentees Alex Oxlade-Chamberlain, Jack Wilshere, Santi Cazorla, Mikel Arteta and Tomas Rosicky.

Wenger revealed after Tuesday’s match that the most serious is the one suffered by amsey, who broke down just 16 minutes after coming on as a substitute for Gabriel.

Mertesacker had earlier been substituted 33 minutes into the match with an eye injury and Gabriel was taken off at the start of the second half with a muscle problem.

Double blow: Cech and Koscielny are already on the sidelines

Double blow: Cech and Koscielny are already on the sidelines

“I’m a bit under shock,” Wenger told BT Sport afterwards. “We lost our two centre-backs and after that we lost Ramsey.

“Mertesacker is not serious, just a bit of concussion. Gabiel looks alright, Ramsey I am a bit more concerned about. It is a muscular [one], a thigh injury.”

Arsenal’s victory over Hull keeps alive their hopes of winning the FA Cup for the third year in a row and means they will host Watford at Emirates Stadium in a hastily-arranged tie on Sunday.

Wenger is already without Cech for a month, while Koscielny has missed the last three matches with a calf injury and has been rated doubtful for the weekend by the manager.

In other Arsenal injury news, the club’s medical team have revealed that Jack Wilshere is close to regaining full fitness.