One day following his early exit against the Red Sox, Mariners left-hander Nick Margevicius was placed on the 10-day injured list with left shoulder inflammation on Monday. In a corresponding roster move, right-hander Robert Dugger was recalled from the alternate training site.

The Mariners were still waiting on the results of Margevicius' MRI exam by the time manager Scott Servais met with reporters ahead of Monday’s four-game series opener against the Astros at Minute Maid Park.

Ljay Newsome, who came on in relief of Margevicius for his second straight outing, is in line to take the vacant spot in the rotation the next time through, which would be on Saturday against the Angels at T-Mobile Park. But that decision hasn’t been finalized.

Newsome pitched four scoreless innings of relief and permitted just two baserunners among the 14 hitters he faced on Sunday -- and he did so on just one days' rest. The Mariners want to gauge how he bounces back before penciling him into the rotation. The right-hander was stretched out more on a starter’s workload in Spring Training. He made four starts in 2020, topping out at 4 1/3 innings.

In the small sample size of 10 2/3 frames in 2021, Newsome has been sharp, with a 1.69 ERA and 0.94 WHIP to go with 11 strikeouts, nine hits and just one walk. His quality of contact numbers have been decent as well.

“That’s probably where we would lean,” Servais said. “I thought he threw the ball outstanding [Sunday against the Red Sox], and Ljay continues to get better. He's been very effective in the bullpen role, and I think our expectations would be real as far as sending him out there, not expecting him to go six or seven innings, but keep us in a ballgame, give us four or five innings, and then take care of business after that with the rest of our bullpen. So, again, that's where we're leaning, but nothing is set in stone yet.”

The ripple effect of the pitching staff will continue with Dugger taking Newsome’s spot as the long reliever, capable of handling 50-60 pitches per game. Claimed off waivers in December, Dugger has been one of two starting pitching insurance arms at the alternate training site, along with Jimmy Yacabonis. Dugger has 11 career outings under his belt, including eight starts with Miami from 2019-20. He’s compiled a 7.40 ERA over 45 innings, averaging 10.8 hits per nine innings.

Dugger pitched the seventh and eighth innings in Monday’s 5-2 loss, giving up just two hits and no walks while throwing 28 pitches.

“Really, an emphasis on his breaking pitches,” Servais said. “He’s always kind of been a sinker-slider guy. He's worked in the curveball and leaning more on the curveball-slider [combination]. It's been pretty good for him, and that's what the focus will be with him going forward. He is a bigtime strike thrower, so he fits perfect in that role.”

The Mariners obviously didn’t want or plan to be at this point with their depth, but the issue has become more prominent in the past two weeks due to James Paxton suffering a season-ending forearm injury and his replacement, Margevicius, out for at least his next turn. Margevicius left his start on Sunday after just 32 pitches, only 13 of which were strikes, while showing fatigue and diminished velocity.

On Sunday night’s charter from Boston to Houston, Servais and pitching coach Pete Woodworth also discussed the possibility of going from a six-man rotation to a standard five-man unit. The Mariners have two scheduled off-days in the first 10 days of May that they could toy with, and a third one slated for May 20.

By that point, their most significant reinforcement would be closer to reaching the Majors. That would be No. 4 prospect Logan Gilbert, who is still being slowly stretched out in Minor League spring training. The Mariners will want Gilbert to make at least a handful of starts for Triple-A Tacoma, and its season doesn’t begin until May 6.

But Servais’ tone on Monday -- and the club’s long-preached discipline of deploying a six-man unit to help govern workloads and preserve health -- suggests they likely won’t go to five, even temporarily.

“You have to look at the whole group. You can't just look at one or two guys,” Servais said. “Certainly, one or two guys are maybe more capable and ready to handle that. But we just have to wait and see. Right now, we're not planning on it. But it's something we have discussed.”