Shields (10-9, 3.43 ERA) had gone 4-0 with a 1.53 ERA over a five-start stretch before getting hit hard in Friday's 16-2 loss to Detroit. The right-hander matched career worsts by allowing 10 runs and 14 hits in 3 2/3 innings, his shortest outing of the year.
"It was not a good outing," he said. "I actually went back and looked at the video, and a lot of my pitches they were hitting were below the strike zone. ... I didn't do my job tonight. You've got to move forward, but it was a terrible job by me."
Kazmir (8-7, 4.17), in contrast, was at his best Friday, striking out a season-high 12 over six scoreless innings in an 8-1 victory over the New York Mets.
"Just to be able to throw my fastball consistently in the location I wanted to, that's something I was very pleased with," said Kazmir, who was 0-3 with a 7.11 ERA in his previous four starts. "We're playing for a playoff spot right now. That's the one thing I'm thinking about when I go out to the mound."
Kazmir will try to help Cleveland (77-67) get back on track following Tuesday's 6-3 loss. Lonnie Chisenhall, Carlos Santana and Michael Brantley went a combined 7 for 11, but the Indians hit into three costly double plays.
"We didn't do damage," said manager Terry Francona, whose team dropped 5 1/2 games behind AL Central-leading Detroit. "We gave ourselves a chance in a lot of innings, but couldn't get the big hit to get the ball rolling."
Alcides Escobar homered and drove in two runs for surging Kansas City (76-69), which went 4 for 8 with runners in scoring position to snap a six-game skid at Progressive Field. Winners in 12 of 17, the Royals are 1 1/2 games behind the Indians and three in back of Tampa Bay for the second wild-card spot.
"We're excited," winning pitcher Jeremy Guthrie said after throwing six sharp innings. "We know there's teams ahead of us. If we win games, we have a chance. If we don't, we don't. The scoreboard watching makes it fun. We know we have to win a lot of games. We have to win series to give ourselves a chance."
While Shields will try to build on Guthrie's impressive effort, he is 1-5 with a 4.20 ERA in 12 career starts against the Indians. He posted a 6.97 ERA in two outings spanning a combined 10 1/3 innings in July.
Mike Aviles is 10 for his last 25 with two homers and a double against Shields, and Brantley is 7 for his last 18. Nick Swisher, though, has been limited to three hits in his last 25 at-bats in their matchups.
Kazmir, who yielded two runs in 6 1/3 innings to beat the Royals 5-3 on July 13, is 1-1 with a 3.86 ERA in three matchups against them this year.
He will need to be careful against Salvador Perez, who is hitting .414 with six homers and 20 RBIs in his last 17 games. Perez homered for his only hit in five at-bats against Kazmir.
Kazmir and Shields spent three-plus seasons together in Tampa Bay from 2006-2009.