TORONTO -- It's reached the point with the Mariners' pitching fortunes that now the fill-in starters need to be filled in for, as Saturday callup Ryan Weber had to be taken out in the fourth inning of his first start for Seattle after feeling tightness in his right shoulder. The Mariners went on to lose, 7-2.
Weber was headed to a doctor in Toronto to have his shoulder examined immediately after the game ended, but manager Scott Servais indicated it could be a serious injury.
"We'll have a better idea tomorrow," Servais said. "But any time a pitcher grabs his shoulder like that, it's pretty significant."
Weber was Seattle's third straight spot starter in the Blue Jays series, following rookie Chase De Jong on Thursday and Christian Bergman on Friday. That trio has been needed with Felix Hernandez, James Paxton and Hisashi Iwakuma all going on the 10-day disabled list over the past 18 days.
A fourth starter, Drew Smyly, has been on the 60-day disabled list since just before Opening Day, leaving the Mariners' MAS*H unit searching for arms. Weber, who'd gone 2-0 with a 0.85 ERA in five starts for Triple-A Tacoma, became Seattle's ninth starter this year and he didn't last long.

The 26-year-old worked smoothly into the fourth inning and had two outs and a 1-2 count on Ryan Goins when he grabbed for his right elbow after his 55th pitch. Servais and the trainers hustled to the mound and Weber was replaced by left-hander Dillon Overton.
Weber allowed three hits and a run in his short duty and left with a 1-0 deficit.
Pitching injuries have been widespread around baseball this year, but the Mariners are now tied with the Blue Jays and Reds for the most starters used in the Majors already at nine each.
"It's been a wild year so far," said Servais. "We're 6-7 weeks into this thing, and had our ninth starter out there today. It's hard to imagine you could ever plan for anything like this. As much depth as we think we created in the offseason, you never think you're going to have to tap into this much. But that's where we're at."
Servais said the club would likely make another roster move on Sunday to add another pitcher in Weber's place.
Right-handed reliever Jean Machi was designated for assignment to open a spot on both the 25- and 40-man rosters for Weber, who pitched in 21 Major League games for the Braves over the past two seasons, including seven starts, and was 1-4 with a 5.15 ERA.
Machi, 35, made five relief appearances with the Mariners after being selected from Tacoma on May 2 and was 1-0 with a 1.17 ERA with four strikeouts and four walks in 7 2/3 innings. The Mariners now have seven days to trade, release or outright Machi to the Minor Leagues.