Craig Gardner has backed Connor Wickham to fill the Sunderland void left by Steven Fletcher, who is recovering from an ankle injury.

PA PhotosConnor Wickham has been hampered by injuries this season

Wickham, who had been linked with a loan move to the Championship, came on for Fletcher during Sunderland's 2-1 defeat at Norwich on Sunday.

And now the former Ipswich player could step in to the starting line-up with Fletcher, signed from Wolves in the summer, on the sidelines.

"It's a big blow to lose Fletch. He's different class," midfielder Gardner said. "Fletch went off at Carrow Road but Connor came on and was brilliant. He has worked his socks off in training, and hopefully he can really push on now."

Black Cats manager Martin O'Neill, whose side face Chelsea on Saturday, said England Under-21 international Wickham had produced an "encouraging" performance at Norwich.

He said: "I thought young Connor Wickham applied himself very well and became a bit of a handful for Norwich. That's encouraging for him.

"He's been out of the picture, he has come in and, asking him to play centre-forward, I thought he did fine."

Wickham said: "I've spoken to the gaffer before and he told me what I had to do, so I have worked my socks off in training and thankfully he had faith in me.

"The manager has told me to hold the ball up and be more aggressive and I've been doing that more in training, and that's why my chance came."

The forward looks set to start against Chelsea, and added: "I've known all along I was capable of coming in and doing a job, and I was excited to be able to get a game.

"That spurred me on to get my head down even more and work. Hopefully, this is the start of my season."