Martin O'Neill is not expecting "miracles" from Louis Saha but is confident that the striker will have a big role at Sunderland.
The 34-year-old signed a one-year contract with the Black Cats just ahead of the start of the new Premier League season.
The Frenchman spent the latter part of the last campaign at Tottenham, but seemed to be on his way out of English football after the expiry of that short-term deal.
"His appetite for the game is fine," O'Neill declared. "In truth there's so many games hopefully he would play in but I'm not expecting miracles from him.
"I'm not expecting him to play every single game. That would be an enormous ask for him, but in the course of time I think he can help us.
"In the last season he played a while for Everton and played some for Tottenham Hotspur and perhaps maybe he thought with family, moving back to France that was it.
"He has told me 'Everyone always has a point to prove' so I think he's ready to do well."
O'Neill hopes to add to his squad before the close of the transfer window, and it is thought that Sunderland have had a series of bids for striker Stephen Fletcher rejected by Wolves.
"We've been making inroads into trying to get some players," O'Neill added.
"Of course it's difficult because if you want a player and you think they're good enough to play in the Premier League the clubs that you're wanting these players from naturally don't want their players to leave. Maybe that's been the difficulty.
"I knew it was going to be difficult but I'm expecting players to be arriving in the next 10 or 11 days."