Theo Walcott believes that Arsenal have a "great opportunity" to retain the FA Cup following a string of high-profile exits in the fourth round.

Manchester City were beaten 2-0 by Championship side Middlesbrough at the Etihad Stadium, while Premier League leaders Chelsea suffered a shock 4-2 reverse to Bradford at Stamford Bridge.

Southampton and Tottenham Hotspur were also knocked out with home defeats to Crystal Palace and Leicester City, and the Gunners host City's conquerors Boro this weekend.

Walcott told the club's official website: "It is a great opportunity when you consider the teams that have gone out [of the competition].

"But Middlesbrough will be tough, they are doing well in the Championship and they might be very similar to Leicester.

"They will be a threat, we can't take them for granted. We need to study their game very closely because if they watched our game here they will fancy [playing] us. We have to make sure we are completely on it because it will be nice for the fans to have a Wembley trip again."

Walcott was on the scoresheet as Arsene Wenger's side recorded a 2-1 win against Leicester City on Tuesday.