Fister returned from the disabled list triumphantly with a six-inning shutout of Colorado on June 16. But he allowed 14 earned runs over 8 1/3 innings in his last two starts. Minnesota hit him for six runs on Monday, while Texas tallied nine runs on June 27.
The right-hander said turning things around is a matter of a "minute detail" he needs to focus on for an entire game. Fister said he needs to keep his arm angle up and make sure his pitches achieve a sinking action, letting him locate down in the strike zone.
"I think it's just a matter of fine-tuning it," Fister said. "Just focusing on getting on top of the ball and driving through it instead of trying to get on the side of it and trying to make it do too much."
Fister isn't blaming rust, though. Saturday will mark his fifth start since returning from a left side injury.
"I can't attest to knocking rust off," he said. "It's just a matter of I need to get some momentum and really just make my pitches."
Chen's last outing didn't unravel until his sixth and final inning against Minnesota last Sunday. He limited the Twins to one run on two hits through the first five before giving up two home runs in a five-run sixth.
The troublesome frame saw the Royals lose a 5-1 lead and the Twins went on to post a 10-8 victory.
"I feel bad," Chen said. "We had a good lead and I feel like I let the game get away from me.
"I should've made better pitches. ... But really I felt like I had all my pitches going and I shouldn't have given up six runs, especially since we were ahead, 5-1."
Royals: Yost hopes to take pressure off 'pen
Kansas City is carrying 13 pitchers on its roster during its 11-game road trip in an effort to support a bullpen that's been overworked this season. But manager Ned Yost is hoping for some longer outings from his starters in the second half of the season.
"We need to find length on our starters a bit more, and the guys are doing a little better with that," Yost said. "[Everett] Teaford and [Luis] Mendoza have gone deeper recently. They've done a good job. [Bruce] Chen is pitching better lately."
Right-hander Luke Hochevar said on Friday that he would be "100 percent" ready to go for his first start following the All-Star break. He sprained his right ankle while covering first base during Thursday's game in Toronto.
Tigers: Cabrera takes his hacks as DH
Manager Jim Leyland gave Miguel Cabrera a bit of a rest in Friday's game, starting him at designated hitter for the third time this season. Playing the hot corner for the first time in five years, Cabrera leads all American League third basemen in games, innings, and starts there.
Austin Jackson extended his hit streak to a career-high 13 games on Friday as he went 1-for-5. He is hitting .400 (22-for-55) during the streak dating to June 24.
Cabrera continued his lifetime tear against the Royals on Friday, going 2-for-4. He is hitting .338 (101-for-299) against Kansas City with 16 home runs and 58 RBIs.
Friday's victory was Detroit's 15th in its last 21 games against the Royals.