Wheeler (elbow) threw a 30-pitch bullpen session Friday but acknowledged the possibility he may not return this season, The Record's Matt Ehalt reports.
He still needs to progress to facing batters before he can begin a 30-day rehab assignment. Pitching coach Dan Warthen estimated that Wheeler would need to face hitters for about 10 days before heading out to a minor league affiliate. The rehab assignment may not last the full 30 days, but he will need to build up his arm strength to the point where he can give the Mets 80-plus pitches per outing. With all of these variables, it seems unlikely Wheeler will be able to return before sometime in September, and it remains possible he does not return at all this season.