No. 8 prospect Stephan lands on IL with back injury

The April injury bug is trickling down from the Yankees to their minor league farm system.

The Thunder placed righthander Trevor Stephan on the 7-Day IL with a back injury Friday. The designation is retroactive to Wednesday, although manager Patrick Osborn said he does not yet know Stephan’s timetable for return.

Stephan, rated by MLB Pipeline as the Yankees’ eighth-best prospect, is the second Thunder pitcher to suffer an injury already. No. 11 prospect Nick Nelson has been on the IL since April 17.

“He had shoulder tightness, but from what I know he’s progressing well in his rehab and we hope to get him out back as soon as we can,” Osborn said.

Stephan has had a patchy start to the year. Through four starts he labored through 14 innings with 21 hits, 12 walks and 14 earned runs.

Also in Friday’s flurry of roster moves, right-hander Brady Koerner went up to Triple-A and three players came from Scranton/Wilkes-Barre to Trenton: right-hander Daniel Alvarez, infielder Wendell Rijo and outfielder Omar Carrizales.

Alvarez has already pitched six innings in Double-A this year, allowing two earned runs while striking out 10. Rijo posted a .264/.316/.472 hitting line in 13 games before going up to Triple-A.

“(Alvarez) has been arguably one of our better bullpen guys, most consistent bullpen guys. If we can label one, he’s been the closer and done a great job,” Osborn said. “Wendell Rijo, having him back is huge for our team. He’s been a really big, consistent bat whether it’s hitting in the two-hole, the seven-hole, the five-hole. He’s had a really nice start to his year.”

Carrizales is a 24-year-old Venezuela native whom the Yankees signed for outfield depth on April 15 after the Blue Jays released him.

“All the reports I have on him is the kid is a good-looking player,” Osborn said. “He can play defense, swings the bat well, plays all three outfield spots. So looking forward to seeing what he can do and help us out.”