Defeat at Deepdale would put an end to City's chances of making the play-offs, while a first away victory since New Year's Day would keep alive the Canaries' faint hopes of extending their season.
Safri, however, may join Paul McVeigh on the sidelines because of a niggling stomach injury. The former Coventry man has suffered a series of minor injuries this term as well as missing most of January for the African Nations Cup.
"Youssef's going to see a specialist over the next 24 hours and after that a decision will be made as to what is required," said manager Nigel Worthington, whio may replace his talismanic midfielder with former Lilywhites man Dickson Etuhu.
One player who will definitely not feature is Jason Jarrett, who cannot play for North End under the terms of his loan from Norwich. He is expected to have played his last game for the Canaries and to join the Lancashire club permanently in the summer.