Cubs put LHP Justin Steele on the injured list with right hamstring strain.

ST. LOUIS — The Cubs put left-handed reliever Justin Steele on the 10-day injured list with a strained right hamstring before Friday night’s game against the Cardinals and recalled southpaw Brad Wieck from Triple-A Iowa to take his place on the 26-man roster.

Losing Steele is a blow. Since making his MLB debut last month, he has been a revelation in the Cubs’ revamped bullpen.

“Justin has a moderate strain,” manager David Ross said. “A little more severe than a mild is what the trainers are telling me.”

Steele appeared to have injured the hamstring in Thursday’s victory over the Nationals while running the bases. He was removed from the game after making his warmup pitches in the seventh inning. He’s 2-0 with a 2.03 ERA in 11 games this season.

Injuries have been an issue around MLB this season, and several Cubs players have gone on the IL over the last few weeks.

“The injuries, I don’t think anybody has a real pulse on why,” Ross said. “There’s all these theories [with] the pandemic — guys were probably training more at home rather than gyms — and you’re away and you’re probably a little less active in the offseasons.

“It’s important that they get rest with the trend we’re seeing. Trying to keep that balance — I think it’s a real competitive advantage. We’re talking a lot about competitive advantages. One is keeping guys healthy this year, and throughout 162 games [it’s] going to be a competitive advantage on the back end.”

Contreras the teacher

The Cubs have gotten a lot out of their young arms this season, with Steele, Keegan Thompson, Adbert Alzolay and Tommy Nance starting to make noise.

Catcher Willson Contreras used to be the young guy on the Cubs’ 2016 World Series team. Now he’s playing a big role in helping the young pitchers as they find their way.

“Whenever there’s a new guy on the mound like Steele or Thompson or a young guy, I feel that responsibility with my job,” Contreras said. “I have more experience in the big leagues and communicate every little detail with them. I want them to learn from Day 1 what adjustments we need to make and how to approach everybody they come up to face. That is something that is my responsibility to let them know, teach them and guide them the right way.”