The former England international has not started a game for almost a month, but came off the bench as Stoke fought back to beat Southampton 2-1 in the Premier League on Saturday.
Stoke manager Hughes was impressed with the impact the much-travelled forward made in his cameo appearance and is taking a cautious approach with the 34-year-old, given that he is not fully fit.
The Welshman said: "Peter's been struggling with groin injury, likelihood is that he will have an operation at the end of the season.
"We're just trying to manage him through games, so 20-25 minutes is probably the max that he can be effective, he came on and certainly was."
Charlie Adam completed Stoke's fightback with a winner six minutes from time at the Britannia Stadium as Southampton missed a chance to go fifth.
