"He's improving every day," said manager Lloyd McClendon. "The doctors are pleased with where he is. I'm not sure when he'll throw off the mound, but he's getting close."
Paxton, who is 5-0 with a 1.75 ERA in six Major League starts, said trainers are telling him not to rush things after he had to shut down following a Minor League rehab start for Triple-A Tacoma in late May when his shoulder tightened up. He initially was sidelined with a strained lat muscle, and he said both issues are being monitored now.
"Everything at the moment is feeling really well, so we'll just take it day by day," said Paxton, who has thrown twice now since being shut down.
Taijuan Walker, the Mariners' other young hurler working back from injury, is scheduled to start Saturday for Tacoma at Nashville.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.