Weaver was hit by a Dustin Ackley line drive in Sunday's fifth inning, then finished the frame and was taken out after giving up a single and a walk in the sixth.
Weaver's next turn is slated for Friday, which comes after Thursday's off-day and marks the opener against the Tigers at Angel Stadium, but that's up in the air at the moment.
Scioscia said Weaver's right shoulder was "a little tender" on Monday morning, though he hasn't received any tests yet.
"We're going to wait and see how it's feeling," Scioscia said. "... Let's get through this series and we'll see how some things set up, particularly with Weave, and then we'll have decisions."
Weaver said after Sunday's 2-1 loss to the Mariners that the shoulder "feels all right" and that the comebacker "didn't really square me up too bad, so it didn't affect anything."
Asked whether he felt the shoulder would affect his start in five days, Weaver said: "No, I don't think so. We'll see."
Weaver, 16-4 with a 2.86 ERA and an American League-low 1.029 WHIP, is expected to be counted on a lot this month. The Angels' ace was penciled in to make seven September starts, lining up mostly on normal rest in order to maximize his usage and line up for either the regular-season finale or, if his team gets there, the Wild Card elimination game.
If Weaver's shoulder affects that, the Angels will at least have some flexibility with three September off-days, and can be more comfortable with a rotation that has performed a lot better as a whole recently.
"The rotation, as much as you want to put stuff in pen, it's always in pencil," Scioscia said Sunday. Pitching coach Mike Butcher "will be ready to go with whatever options present themselves, but right now, we're going to see how things set up with Weave."