Right-hander Taijuan Walker opened the Arizona Fall League with four strong innings for the Surprise Saguaros, but Mariners farmhand Stephen Landazuri gave up three runs in the eighth inning in a 5-4 loss to the Peoria Javelinas.
Walker held Peoria to one run and five hits Tuesday in Surprise, Ariz., while striking out five and walking none. He threw 44 strikes in 57 pitches before handing a 3-1 lead to the bullpen.
Several other Mariners prospects had encouraging Fall League debuts.
Patrick Kivlehan started at first base and hit a homer in the third inning against Peoria starter Kyle Zimmer of Kansas City, while third baseman D.J. Peterson contributed an RBI double in the sixth inning.
Catcher John Hicks went 1-for-3 with a walk.
Landazuri, 22, inherited a 4-2 lead to start the eighth inning but gave up four hits. Hunter Renfroe of the San Diego had an two-out RBI single before Hunter Dozier of Kansas City followed with a two-run double.
The Mariners selected Landazuri, a right-hander, in the 22nd round of the 2010 draft. He was 6-5 with a 4.33 ERA this season in 19 starts at Double-A Jackson.
The Fall League bills itself as a finishing school for top prospects and runs through Nov. 15. It consists of six clubs in the Phoenix area, which are each comprised of players from five organizations.