SEATTLE -- It’s going to be a while before Justus Sheffield returns to the Mariners’ rotation.

The 25-year-old was placed on the 10-day injured list on Wednesday with a left forearm strain, but Mariners general manager Jerry Dipoto revealed on his weekly radio hit that Sheffield is also dealing with a Grade 2 oblique strain.

"Frankly, from a time perspective, the more concerning of the two is probably the oblique,” Dipoto told ESPN 710 Seattle.

Mariners manager Scott Servais said before Thursday’s series finale against the Yankees that he did not anticipate Sheffield starting when he’s first eligible to come off the IL on July 21, when the club is in Colorado.

“I think he's going to be down for a little while,” Servais said.

Sheffield first approached the Mariners with his injury issues following Tuesday’s start against the Yankees, when he surrendered six earned runs and didn't make it out of the second inning. That extended a stretch of poor starts to five, over which he’s gone 0-4 with an 11.36 ERA. He told reporters postgame that he’s not been 100 percent.

This is Sheffield’s first time on the IL since an 11-day stint in 2018 while at Triple-A in the Yankees’ system.

For now, the quick fix for Sheffield’s rotation spot will be to roll out a bullpen day for his next turn through on Sunday against the Angels. Servais said that they’ll opt for an opener who can get them one time through the order, making Robert Dugger, who has filled that role multiple times this season, the likeliest candidate.

But long term, Seattle could be in a tough spot given the dearth of its starting pitching depth. Justin Dunn has begun throwing from 60 feet, but he’s still at least two weeks away and needs a rehab assignment. The club has already switched from a six-man rotation to five to account for Dunn’s injury.

“We’ll mix and match after [Sunday], is probably where we'd head, but we'll have to wait and see how the upcoming games play out who's available for us,” Servais said.

Servais lobbies for Crawford
J.P. Crawford could have one final avenue to the All-Star Game after all. Seattle’s breakout shortstop would be a prime candidate to take a spot on the American League roster after the Astros’ Jose Altuve and Carlos Correa opted out early Thursday. Correa wants to spend the break with his pregnant wife and Altuve is dealing with a left leg injury.

Servais texted Kevin Cash, the AL’s manager by virtue of leading the Rays to the AL pennant last season, to lobby for Crawford.

“I do think J.P. is very deserving of going to the game,” Servais said. “I think he's a great fit. A young player kind of breaking out with a ton of energy, it's kind of what the All-Star Game should be about; guys that want to be there, want to play, want to showcase their skills, and they want to represent their team, their community, where they're coming from. And I know J.P. is very proud of wearing a Mariner uniform. So, hopefully that all comes together.”

Crawford felt that he deserved to be an All-Star and said this week that he was “hurt” that he wasn’t selected.

“I also do understand that Kevin Cash does not make the final call,” Servais said. “How the All-Star Game works, his selection and how those rosters are put together is much different than how it used to be. I think back in the day, the managers had a lot to say, and I don't think that's the case anymore.”