DiPietro, out since March 25 when he sustained his second concussion, travelled to Buffalo in time to watch the Islanders' 4-1 loss to the Sabres on Thursday. Coach Ted Nolan said DiPietro will practise Friday, then the team will determine whether he can play Saturday.
The best-of-seven series shifts to Long Island for Game 3 and 4 on Monday and Wednesday.
DiPietro missed the final seven games of the regular season.
Minor-league player Wade Dubielewicz has filled in, helping the Islanders win their final four regular-season games, including a 3-2 shootout win over New Jersey on Sunday to clinch the East's eighth and final playoff berth.
Dubielewicz kept the Isles close against the Sabres on Thursday, stopping 20 of the first 22 shots he faced, and 31 overall.
The Isles rely on DiPietro, though, who went 32-19-9 during the regular season, and had five shutouts. The 25-year-old goalie is in the first season of a 15-year deal with the Islanders.