Slowly but surely, the Cubs are returning to health.

Veteran starters Marcus Stroman and Drew Smyly returned to the rotation last weekend and now the right side of the infield on Opening Day is following suit.

Frank Schwindel was activated off the IL Thursday after missing nearly a month with a back injury. Nick Madrigal could be close behind after suffering a setback in his recovery from a groin injury.

To make room for Schwindel on the roster, the Cubs placed Andrelton Simmons on the 10-day IL with a right shoulder injury. The issue has bothered the veteran infielder since Spring Training and cropped up again after a throw in Los Angeles.

Schwindel wasn’t in the lineup for Thursday’s series opener with the Mets but David Ross said he would be available off the bench. He’ll likely play Friday when the Cubs have a day game after a night game and after Sunday, the team is off for four days for the All-Star Break, so there’s a natural opportunity for Schwindel to be eased into action.

He played 5 games with Triple-A Iowa on a rehab assignment, collecting a homer and a single in 18 plate appearances.

He was happy with his at-bats in the minors but the big thing for Schwindel is his health.

“I’m hoping [the back] holds up,” he said. “Never was 100% from spring but tried to grind through it. It got me that one day but doing a lot of rehab since. Good program we’re on. I think we’ll be good to go.”

Schwindel missed a week in Spring Training with back tightness and was never able to fully eradicate the issue before suffering another bout while attempting to run out a groundball on June 17 at Wrigley Field.

Now that he finally feels 100%, he is optimistic he can produce at a level closer to what he showed in the final two months of last season (.342 AVG, 1.002 OPS).

“Oh absolutely. That’s the plan,” Schwindel said. “Feeling good. That’s half the battle and then just go from there and put together some good at-bats.”

Schwindel got off to a tough start in 2022, hitting .200 with a .535 OPS through the first 29 games. He was actually optioned down to Iowa for a day in May before the Cubs needed him again when injuries struck.

In the 35 games before he landed on the IL, Schwindel was hitting .263 with a .761 OPS and collected 6 homers and 24 RBI. That type of offense would be helpful to the Cubs lineup and with renewed health, Schwindel is hoping he can deliver.

Madrigal’s season has also been marred by injury. First it was a back injury that kept him out of action for most of May and then in mid-June, he strained his groin muscle.

He had just began a rehab stint with Iowa but had to come out of Sunday’s game when he felt tightness in the same area while running the bases.

After a couple days off, Madrigal said he feels “pretty normal” now and has been able to do some baseball activities at Wrigley Field, including taking batting practice.

The plan for Madrigal will be to head to Arizona for a few days during the All-Star Break next week to continue building up. If all goes well, he could go on a rehab stint for a couple of games before rejoining the big-league team.

“The biggest thing was during the All-Star Break, they didn’t want me shutting down,” Madrigal said. “They wanted me to keep ramping up so I am able to get back with the team sooner.”

Madrigal was the 4th overall pick in the 2018 MLB Draft and was a centerpiece of last summer’s trade that sent Craig Kimbrel to the White Sox. The 25-year-old second baseman was recovering from a hamstring injury when he first joined the Cubs and has only been able to play in 31 games this season.

He hopes he can get into a rhythm in the second half of the year and showcase the player he was with the White Sox (.317 AVG, 764 OPS in 83 games).

“I can’t think about the games I’ve missed or the time I’ve been away,” Madrigal said. “I gotta keep my mind in the right place. I’ve been anxious to get back out there but I’m not gonna get down on myself at all. There’s 80-something games left. I’m hoping to be in there for a good amount of those.”