The 33-year-old is out of contract in the summer and has made just 10 appearances this season.
But Appleton, who handed the former Birmingham man his first start since October for the FA Cup quarter-final replay against Millwall after he impressed in the original tie, has told the midfielder to prove he deserves a new deal over the remaining 10 fixtures.
"I think he has shown enough in the last game and a half to know that he has got enough ability to make sure he stays in the side," Appleton told the club's official website.
"We just need to keep him fit, that is the biggest thing because he could be very influential for us over the remaining 10 games.
"From his point of view he's got 10 games to prove that he deserves the opportunity to get a new contract.
"I think if he performs the way he has done in the last one-and-a-half games then he'll certainly be in with a very good shout."