Paxton, ranked No. 89 on MLBPipeline.com's Top 100 Prospects list, opened the season with the Mariners. After making two starts, he landed on the disabled list due to a strained lat muscle in early April. Paxton made a rehab start May 24 with Triple-A Tacoma, but he developed soreness after throwing thee innings and was again shut down.
After nearly two months, Paxton returned to the mound Thursday. He struck out two batters, allowed two runs on two hits and a walk.
The Mariners selected Paxton in the fourth round of the 2010 First-Year Player Draft. He went 8-11 with a 4.45 ERA and struck out 131 batters in 145 2/3 innings with Tacoma last year. That performance earned Paxton a September callup, leading to his Major League debut Sept. 7. If all goes well on his latest rehab assignment, he could return to Seattle sometime in the second half.