SAN FRANCISCO -- Rookie infielder Matt McLain was placed on the 10-day injured list after undergoing an MRI that revealed a right oblique strain on Monday, a major blow to the Reds as they open a three-game set with the Giants that could make or break their push for a National League Wild Card spot. 

McLain received his MRI results around noon on Monday, and the team is still determining whether it's a Grade 1 or 2 strain. Without knowing the severity of the injury, manager David Bell declined to set a timeline but said he's hopeful that McLain will play again this season.

"We're really hoping it's on the mild side and he can return quickly," Bell said. "I think he'll have a chance to get it better quick now, because he was playing with it and he can really get on top of the treatment."

McLain, who had taken over at second base since Jonathan India was sidelined at the end of July, had felt something in his side over the Reds' past couple of series but was able to play through the discomfort. In particular, taking and swinging through pitches hurt, McLain said, whereas he didn't feel much pain when making contact.

That changed over the weekend, when the pain built to where McLain could no longer deal with it.

"It got to the point where it hurt to do just about everything," McLain said, "so I had to say something."

McLain informed the team on Sunday night, which led to his MRI and subsequent placement on the IL.

"It's just one of those things where players play through all kinds of stuff," Bell said. "It's still early in his career. Never having that injury, I don't think he knew what it was. He just thought it was normal soreness, and it just got to a point where he was feeling it too much."

Since McLain made his big league debut on May 15, Cincinnati is 50-42, tied for the seventh-most wins in the Majors in that span. The rookie infielder has been the team's most valuable player in terms of both bWAR (3.6) and fWAR (3.3).

Along with teammate Spencer Steer, who started at second base on Monday, McLain has been one of the top rookie players in the game. Through Sunday, his .864 OPS ranked second-best among all rookies with at least 400 plate appearances, trailing only Arizona's Corbin Carroll.

With the Reds entering Monday 1 1/2 games out of the third NL Wild Card spot, the loss of McLain could not come at a much worse time.

"That's the worst part, the position that we're in," McLain said. "Unfortunately, that's part of it. I'm going to do everything I can to get back as soon as I can. It sucks, for sure. But this team's more than capable without me. I'm not the team or anything, so we have the pieces and we have everything we need to go win games."