"I'm excited, excited to watch him," manager Eric Wedge said. "I know he's excited to pitch, as well he should be. It's always fun to watch a debut, especially when it's a starting pitcher."
In Triple-A, Paxton excelled after a rough start, leading the Rainiers in wins, starts, innings and strikeouts at the time of his callup. The Mariners selected the University of Kentucky product in the third round of the 2010 First-Year Player Draft. The hard-throwing lefty can reach 98 mph with his fastball, and also utilizes a cutter, curveball, and changeup.
"I feel like I've kind of done my part in the Minor Leagues, learned a lot of things," Paxton said. "I definitely feel like I'm ready for a shot up here and I'm just really excited about it and I'm ready to go."
Paxton, who is ranked as the Mariners' No. 6 prospect according to MLB.com, is a member of Seattle's "Big Three" pitching prospects. Walker, the group's leader, made his big league debut on Aug. 30th and excelled, allowing just two hits and one unearned run in five innings. Danny Hultzen -- the No. 2 pick in the 2011 Draft -- has missed much of the 2013 season with injuries, but pitched two perfect innings for the Rainiers on Sunday.
Paxton will be the fourth rookie to start a game on the mound for the Mariners this year. Brandon Maurer started the year in the Major League rotation, leap-frogging Tacoma after ending last season in Double-A. Major League hitters punished Maurer in his first attempt in Seattle, and he was demoted to Triple-A before reappearing in Seattle as a member of the bullpen. The Mariners hope that he can reestablish himself as a starter after the season in the Arizona Fall League.
Erasmo Ramirez, a rookie who also saw time in Seattle last season, has made nine starts for the Mariners this season, going 5-1 with a 5.07 ERA. While Ramirez struggled to stay in games early, he's thrown 25 2/3 innings over his last four starts with a 2.81 ERA.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. Jacob Thorpe is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.