MINNEAPOLIS -- The Twins placed Royce Lewis on the 10-day injured list on Friday with a left hamstring strain that is expected to sideline him for the remainder of the regular season -- and, at this point, all they can do is treat him, wait and simply hope that he heals quickly enough to be ready for the postseason.

But it’s simply too early to know more than that.

“He’s optimistic, like he always is, but we’re going to see just how he’s probably swinging the bat,” manager Rocco Baldelli said. “If he can swing the bat without compromising his hamstring in any way, then we can have a discussion about what he’s capable of. If he can’t swing the bat, then he can’t swing the bat -- and that kind of answers that question for us.”

The Twins announced that Lewis’ hamstring strain is on the more significant side of a Grade 1 strain, which is considered the least severe of the three grades. They will have a very tight timeline to evaluate him in the 11 days that remain before they make a last-minute decision as they lock in their roster for a potential American League Wild Card Series on the morning of Oct. 3.

In that time, they will continue to treat the injury and evaluate it on a day-to-day basis while seeing if -- and how much -- he can run and hit. If he’s even able to hit, there could be conversations about a designated hitter role in the AL Wild Card Series.

“There is a world with hamstring strains where you can hit but you can't really push the running and the defense, so that would be a factor,” president of baseball operations Derek Falvey said. “If he can do one-half of the game and not the other, we just have to factor that into how we think about the roster.”

It’s impossible to overstate the importance of Lewis to this team’s success. He has already set the Twins’ record for most grand slams in a season (four), and that tracks with his overall productivity in meaningful situations this season. Lewis is slashing .309/.372/.548 for a team-leading .921 OPS with 15 homers. His 52 RBIs are third on the team, despite having played in only 58 games this season.

After returning from a second straight season lost to a torn ACL and an oblique strain, Lewis quickly established himself as the club’s everyday No. 3 hitter and the clubhouse’s emotional focal point. He sustained his most recent injury by fouling a pitch off in the eighth inning of the Twins’ victory over the Reds on Tuesday at Great American Ball Park.

Minnesota is also without Carlos Correa, who is on the IL while waiting for the discomfort from the ruptured plantar fascia in his left foot to subside, but the club is fully expecting Correa to return for the postseason. The Twins are also waiting to see what, if anything, they can get from Byron Buxton, who is getting more game reps with Triple-A St. Paul.

So several significant injury questions remain in the lineup -- but none loom larger than that of Lewis.

“We need to be ready to make a playoff push, so I'm going to try to help these guys out as much as I can if they need me,” Lewis said. “At the moment, the way we're banging, they don't need me. So I'm just excited to cheer them on and be excited to see what they do.”