Luis Severino and Dellin Betances haven’t thrown a pitch in the Major Leagues this season. Which means almost nothing -- or potentially everything. The Yankees believe both right-handers have a chance to contribute at some point this month and possibly in the postseason. That kind of talent is the equivalent of a blockbuster trade.

Welcome to September’s X factor. That is, stars getting healthy and giving their teams a final boost into the postseason. Some of them could push a contender or two closer to the playoffs. Others will be fine-tuned for possible prominent October roles.

We’ve already seen the likes of Carlos Carrasco, Sean Doolittle, Brandon Nimmo and Brent Suter return in the last few days, and here’s a look at nine other players capable of changing the outlook of these final two months:

1) Tyler Glasnow, RHP, Rays: Glasnow came out of his second rehab outing on Monday saying he’s ready to return to the big leagues after a right forearm issue sidelined him four months. He was one of MLB’s best starters before the injury: 0.910 WHIP, 1.86 ERA, 10.24 strikeouts per nine innings. With the Rays, Indians and A’s fighting for the two American League Wild Card spots, he would be a huge boost for the Rays.

2) Blake Snell, LHP, Rays: The 2018 AL Cy Young Award winner could be 10 days away from pitching in the Major Leagues after undergoing left elbow surgery in late July. Rays manager Kevin Cash could piggy back Glasnow and Snell in games as both build up endurance.

3) Luis Severino, RHP, Yankees: He’s on track to pitch in the Majors in the final couple of weeks of the regular season, and if there are no setbacks, he could be a significant addition to the Yankees' postseason staff.

4) Dellin Betances, RHP, Yankees: He appears to be making steady progress toward returning from shoulder and lat injuries, and if he returned just for the final 10 days of the regular season, that would give him time to prepare for the postseason.

5) Jimmy Nelson, RHP, Brewers: He’s probably the biggest X factor of all with his ongoing battle back from major shoulder surgery. He missed all of the 2018 season and made four appearances in June before going back on the IL. Nelson looked good in his final appearances in the Minors, but as he told reporters, he must prove he can do it in the Majors. He would be a huge boost to Milwaukee’s postseason hopes.

6) Ryan Pressly, RHP, Astros: The All-Star reliever is in the early stages of recovery from right-knee surgery, so there’s no timetable for his potential return. That’s suddenly more important with Astros closer Roberto Osuna having allowed runs in eight of his 19 post-All-Star break appearances.

7) Carlos Correa, SS, Astros: He removed himself from a game on Aug. 19 with back tightness and hasn’t played since. The Astros hope he can return at some point in the regular season, and in his most recent comments, Correa said he’s confident of doing that.

8) Robinson Cano, 2B, Mets: The Mets are still in contention for an NL Wild Card berth and play 15 of their final 24 games against other contenders. Cano was back in the lineup in Wednesday's finale against the Nationals, and he picked up where he left off after mashing a two-run homer in the fourth. His return from a hamstring injury gives the Mets lineup (or bench) a more formidable look.

9) Jed Lowrie, 2B/3B, Mets: He was arguably the Mets’ biggest free agent signing last winter, but hasn’t played all year as he has battled various ailments. He’s been playing in rehab games in Triple-A, and while expectations are low for 2019, he’s an accomplished switch-hitter who could provide an intriguing weapon off the bench.