Walker (10-7) suffered a cramp in his right hip flexor after working 6 1-3 innings. Walker, who struck out six, experienced discomfort while facing Chicago’s Adam LaRoche and walked off the field under his own power after being examined by a team trainer.
Tom Wilhelmsen pitched the ninth to earn his fifth save in as many opportunities.
The Mariners snapped a scoreless tie in the sixth with two solo home runs. Seager, who entered Friday’s game hitting .196 in August, led off the inning with a homer to right off White Sox starter John Danks (6-12).
Two batters later, Gutierrez drove his homer to left, giving Seattle a 2-0 lead.
Danks scattered seven hits over six innings, struck out five and took his third loss in his last four outings.
Chicago, which finished with four hits, loaded the bases with one out in the seventh after Walker left the game when LaRoche walked and Alexei Ramirez singled. But Carson Smith, who relieved Walker and pitched two scoreless innings, got pinch-hitter J.B Shuck to ground into an inning-ending double play.
Mariners right fielder Nelson Cruz, who entered the game having reached base in a career-high 37 straight games, saw that streak end after going 0 for 5.
Mariners: Seager returned to the lineup after being given a day off to rest in Thursday’s series opener. . LHP James Paxton (strained left middle finger) was scheduled to make a rehab start at Triple-A Tacoma on Friday. Paxton has been sidelined since the end of May. . Struggling C Mike Zunino was optioned to Triple-A Tacoma on Friday and the Mariners called up C John Hicks from Tacoma.
White Sox: Entering Friday’s game, RHP Nate Jones pitched in consecutive games for the first time since returning in early August after undergoing Tommy John surgery in July, 2014.
Mariners RHP Hisashi Iwakuma (5-3, 4.29 ERA) will be going his fourth win in his last five outings while White Sox RHP Jeff Samardzija (8-10, 4.75 ERA) hopes to end a career-worst five-game losing streak. His last victory came on July 28, against Boston.