SEATTLE -- The Mariners’ starting pitching depth was already a significant concern entering this weekend’s series against the Angels, and those issues became even more pronounced following Ljay Newsome’s eight-run outing that led to a 10-5 loss on Saturday at T-Mobile Park.

Newsome gave up eight runs, including three homers, against the 15 batters he faced over two innings and prompted manager Scott Servais to turn to a taxed bullpen one day after it had thrown five innings. Those relievers were expected to be leaned on given that Newsome was on a pitch threshold of just 75-80, but he wound up being pulled for long man Robert Dugger far earlier than Servais would’ve hoped, after just 52 pitches.

Newsome’s night got off to a promising start when he struck out David Fletcher looking, then he worked Shohei Ohtani into a two-strike count. But Ohtani waited out a walk, then Mike Trout ambushed a center-cut fastball and crushed it 411 feet to straightaway center for his 28th homer at T-Mobile Park, extending his mark as the most in the venue’s history by a visiting player. And things snowballed from there.

Seattle’s righty gave up two more homers, both to Jared Walsh, and a pair of leadoff singles in the second that led to RBIs via a sacrifice fly by Fletcher and a groundout by Ohtani. Of the 12 balls put in play against Newsome, seven were classified by Statcast as hard-hit (anything 95 mph or higher).

"Ljay lives at the top of the strike zone, and if it gets in that happy zone, I say, it's not quite at the top or a little bit higher, that's when he gets in trouble,” Servais said. “And he is a fly-ball pitcher. The ball is going to go in the air when he does get squared up, for the most part.”

Newsome doesn’t possess overpowering velocity, but his ability to locate his fastball has been on display over his previous four outings, all in relief. Entering Saturday, opposing hitters were batting just .167 against his four-seamer, per Statcast, and his overall quality of contact metrics were in the 84th percentile. But that command wasn’t there on Saturday.

“I was finishing a lot of them in the middle of the plate,” Newsome said. “That’s not my game. I usually stay to the edges, but I kind of fell right in the middle. When the command is not perfect, I just have to mix it up more and just I was throwing a lot of fastballs just right down the middle.”

While Newsome and the Mariners will want to flush this one, his outing underscored the state of the rotation, which has concerns regarding its depth. Newsome was starting in place of Nick Margevicius, who had been starting in place of James Paxton, who was earmarked to be a top-of-the-rotation arm when the original six-man rotation broke camp in Arizona.

Margevicius has left shoulder inflammation and is scheduled to undergo further evaluation in the coming days, but he’s still at least a few weeks away in a best-case scenario. Paxton underwent season-ending surgery two weeks ago. And Marco Gonzales’ left forearm strain this week will likely cost him at least a month.

So, where does Seattle go from here?

The Mariners have not yet said who will take Gonzales’ spot in the rotation for his next turn on Monday against the Orioles at T-Mobile Park. Dugger was a likely candidate given his higher pitch threshold, but that’s no longer an option after he threw 51 pitches on Saturday, unless he were mixed in as part of a bullpen day. Regardless, the ‘pen will likely be leaned on heavily because, like Newsome, Dugger is not as stretched out.

Furthermore, even with Newsome holding his spot in the rotation, by not going deeper on Saturday, he won’t be as stretched out for his next scheduled start.

The alternate training site roster is in the process of reporting to Triple-A Tacoma. Among that pitching staff, Jimmy Yacabonis is the lone arm with a starter’s profile. The waiver wire could possibly come into play at some point if the Mariners stick with a six-man rotation.

No. 4 prospect Logan Gilbert is still a ways away, given that the Mariners want to allocate him for at least a few starts at Triple-A before making the Major League leap. Gilbert was up to four innings and 74 pitches in his most recent outing in Minor League spring training on Tuesday.

The Mariners are heading toward a sun-soaked Seattle summer, but their rotation might have to weather its current storm for the time being.