Walker, 21, was shut down last Tuesday after feeling some tightness in his recovering right shoulder as he was preparing for his third Minor League rehab start. Paxton, 25, was pulled from his start on April 8 with a strained lat muscle behind his left shoulder and is also on the 15-day disabled list.
Manager Lloyd McClendon said Monday the prognosis for Paxton would be 6-8 weeks from the time of his injury until he was healthy and ready to pitch again, which would put him still 4-6 weeks away from returning.
But Paxton said he feels good in the rehab work he has done so far and is optimistic he'll be cleared to start playing catch soon.
"Once I get told I can start to throw, then we'll put together a throwing program," said Paxton, who was 2-0 with a 2.25 ERA in his two starts before the injury. "I'm not sure how long it's going to take. But hopefully it won't take quite that long and I'll be able to build it up pretty quickly and be back at it soon."
Walker was close to joining the big league club when he felt what the Mariners are calling "an impingement" in his shoulder. Walker said tests have shown there is only inflammation and no structural problems. But while the young right-hander says he feels much better the last few days, he acknowledges the frustration over his latest setback.
"I came off a pretty good start and was feeling really good," said Walker, the No. 6 ranked prospect in baseball by MLB.com. "All my pitches were feeling great. And then I just woke up and it just wasn't feeling right. It didn't feel normal. I didn't want to go out and push anything. I probably could have pitched, but it probably wouldn't have been the smart thing to do."
Both youngsters have just been doing rehab work since being shut down. For Paxton, the Mariners' No. 3 prospect, that has meant strengthening exercises along with stretching and massaging the lat muscle. But like any pitcher, what he really wants to do is pick up a ball and fling it to see how everything feels.
"I want to throw pretty bad right now," Paxton acknowledged. "But I'm sticking to the process and making sure we do it right."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. Brian McTaggart contributed to this report. Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. This story was not subject to the approval of Major League Baseball or its clubs.