Paxton threw a bullpen session on Saturday, but was still feeling discomfort in the arm on Monday and manager Scott Servais and the training staff decided to delay his next outing.
"He feels a little tightness in that forearm," Servais said. "He got smoked the other day. So we're going to do the right thing and give him a little more time. He wants to go, he wants to take the ball, but we've got to do the right thing here. He threw his bullpen the other day at about 75 percent, but just listening to him and talking to [trainer Rick Griffin], we think it's the right thing to give him a few more days and see where he's at."
The Mariners were already shy one starter with Taijuan Walker having been demoted to Triple-A Tacoma. Servais said no decision has been made yet on who'll get the ball on Wednesday, though Joe Wieland appears the logical choice as he's still on the 25-man roster after making one spot start on Friday in a 6-3 loss at Oakland.
Walker isn't a candidate as he started on Saturday for Tacoma and won't be available again until Thursday at the earliest.
Paxton also isn't a candidate for Wednesday's game as Servais said he'll be given more time to heal. If a decision is made to put Paxton on the disabled list, he'd be out until at least Aug. 23, though that would open up a spot on the 25-man roster for another starter.
Servais said the injury is the result of bruising caused by the line drive that hit Paxton flush in the elbow after he'd thrown 8 1/3 innings and allowed just one unearned run in a 3-1 win on Aug. 7 over the Angels at Safeco Field.
"He had swelling in the elbow and it's kind of moved into his forearm a little bit, which is very natural," Servais said. "That's where the blood usually goes. We want to make sure he has no reservations about taking the ball and going out there and being able to compete at close to 100 percent."
The Mariners went two months without ace Felix Hernandez earlier in the year, lost Walker for nearly a month with tendinitis in his foot and spent time with Wade Miley and Nathan Karns on the DL as well in a season when they've used 12 different starters.
Miranda, acquired from the Orioles for Miley on July 31, has gone 1-0 with a 3.86 ERA in seven innings over two outings, including one spot start. Now he could get a longer run in the rotation, along with Wade LeBlanc, another midseason addition to a rotation that has only two of its original members in Hernandez and Hisashi Iwakuma.
"It's challenging," Servais acknowledged. "Teams have done it before. You're trying to plug guys in there to keep you in games and suck up innings. Fortunately for us, our bullpen has been very good lately. So if we can get to those guys in the sixth, seventh, eighth, ninth inning, we're in pretty good shape.
"But right now, we're finding guys to go in there. Miranda threw the ball well for us early and I feel good about putting him in there. If it's Wieland or somebody else after that, we've got other guys. They don't have the experience or wherewithal, but that's what you've got to have. You've got to have a lot of people step up that you're not counting on and we'll be OK."