For the first time this season, Alec Mills is on the Cubs’ active roster.

The team activated the veteran right-handed pitcher off the 60-day IL Tuesday before the series in Baltimore began. Anderson Espinoza was optioned to Double-A Tennessee to make room on the roster.

Mills initially landed on the shelf with a low back strain before Opening Day and as he was recovering, he encountered a quad injury.

“I was just working out after a bullpen and it just grabbed on me pretty good,” Mills said. “I had to take maybe a couple weeks off and build back up. It’s been a long process.”

Over the last couple weeks, the 30-year-old made 3 rehab starts with Triple-A Iowa including last Wednesday when he threw 52 pitches over 5.2 innings.

Mills spent time around the big-league club in Chicago after that outing and said last Thursday he was on target to make one more rehab start with the hopes of building up to 5 innings and about 75 pitches.

But the Cubs had an opening on the roster now and Mills was able to reach those totals in Tuesday’s 9-3 loss. Coming in as relief for starter Keegan Thompson, Mills tossed 73 pitches over 5 innings against the Orioles, allowing 2 solo homers and striking out 6 batters in an impressive season debut that saved the Cubs’ bullpen. 

Mills has operated as a swingman over the last few seasons in Chicago and will continue to do the same this year.

Mills has made 37 starts and 22 relief appearances with the Cubs since 2018. He has been more effective in the rotation (4.45 ERA) than out of the bullpen (5.24 ERA) but his ability to do both is an asset for the team.

“Millsy’s like the Swiss Army knife of the staff,” David Ross told Taylor McGregor Tuesday. “He’s done so much for us — start, relieve, has closed out a game before. He’s got a pretty good resume in a short big league career so far. Got a no-hitter included in there. He’s gone through a lot of adversity to start the season with trying to build him back up and getting the quad injury in the middle of his rehab assignment.

“We’re glad he’s back. He’ll be a valuable piece. He does a lot of things so it’s important for us to get him back. Gives us more depth in our bullpen.”

The Cubs lined up their rotation to send Keegan Thompson and Marcus Stroman to the mound Tuesday and Wednesday nights in Baltimore. The pair of off-days on Monday and Thursday provide some flexibility for Ross and Co. as they rearrange their pitching staff.

The Cubs won’t need a fifth starter until June 14 (next Tuesday) and at that point, the team can either call upon Mills or rookie Matt Swarmer after back-to-back quality starts to begin his career.

Mills was 6-7 with a 5.07 ERA in 119 innings last season.

In other injury news, the Cubs roster may have more reinforcements on the way soon in the form of Yan Gomes, Seiya Suzuki and Jonathan Villar:

#Cubs injury updates:
-Seiya Suzuki, Yan Gomes & Jonathan Villar took BP today. All progressing.
-David Bote was pulled from rehab assignment with dizziness. Will be evaluated.
-Sean Newcomb will throw again in a rehab game Wednesday.

— Taylor McGregor (@Taylor_McGregor) June 7, 2022

Gomes hasn’t played since May 23 after injuring his oblique, but the Cubs are encouraged where he’s at right now.

“Yan’s doing well. Basically 100%,” Ross told McGregor. “We want to put him through all the tests, try to get him some live looks, maybe some check swings in there with the oblique is important. He threw to bases before we left home, he threw to bases again today. He’s run the bases, played catch, hit consistently. Seems to be doing really well and progressing on really nicely.”

Suzuki sprained the ring finger on his left hand May 26 in Cincinnati and has missed time since. 

“Seiya’s coming along,” Ross said. “He hit as well. Still feels it a little bit in the finger but hopefully BP tomorrow and he went through a full day’s work today. We’ll see how he presents tomorrow but he’s getting really close.”

Villar has missed the last couple weeks with a mouth injury after getting injured in the workout room. He is also taking swings and nearing a return as the Cubs inch toward full strength.

“We’ve got some guys that are really, really close and hopefully we can get them active soon,” Ross said.