The Seattle Mariners' right-hander allowed three hits before leaving with an injury in the seventh inning and Kyle Seager and Franklin Gutierrez both had three hits and a homer as the Mariners beat the White Sox 2-0.
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. He fell to the ground after delivering a pitch, but walked off the field under his own power after being examined by a team trainer.
"I just cramped up," said Walker, who was initially scared by the injury. "(My leg) gave out on me."
By that point of his night, though, Walker had done his job.
"He shut (the White Sox) down," manager Lloyd McClendon said. "He shut them down."
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. Before Friday, Danks hadn't allowed a home run since June 17 — the same day he suffered his last home loss before giving up the two earned runs against the Mariners.
"It's a team game — everybody's got to do their job," Danks said. "There's been plenty of times I didn't hold up my end of the bargain. . It's frustrating."
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.
"The way it was hit to me, it was a lot quicker, I thought, to go home than to go to second," said Seager, who fielded the ball at third and fired home before catcher Jesus Sucre threw to first to complete the double play.
Said McClendon: "It was absolutely the right play to make."
Mariners right fielder Nelson Cruz, who entered the game having reached base in a career-high 37 straight games, saw that streak - the longest in the AL this season - end after going 0 for 5.
Seattle also struggled with men on base, stranding 10 runners.
"We were lucky to win," McClendon said.
STAYING IN THE PRESENT
After Mariners GM Jack Zduriencik was fired Friday morning, McClendon said before the game that he couldn't allow himself to be consumed to the possible uncertainty of the future. "You come out today and try and win a ballgame," said McClendon who declined to reveal what he told players during a meeting Friday that also included team president Kevin Mather. "After this day is over, you go home, re-charge and come out tomorrow and try to win a ballgame."
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 for 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.