"I think it's just command more than anything," Yost said. "I asked [catcher Salvador Perez] what the deal was [tonight] and he just said there were a lot of center-cut fastballs."
After a 1-2-3 first inning, Kennedy allowed a home run to Matt Olson in the second on a 2-0 four-seam fastball.
The real damage came in the third, when the A's rocked Kennedy for seven runs. Olson took an 0-2 Kennedy fastball deep into the right-field fountains for a three-run blast -- Statcast™ projected it to travel 456 feet.
"I literally don't think you could do that again if I just threw pitches down the middle," Kennedy said of the third inning. "You watch batting practice and usually guys get themselves out … and that's without guys changing up speeds. It's frustrating."
While Kennedy's struggles have mounted, right-handed reliever Scott Barlow turned in another effective outing.
Barlow, signed as a Minor League free-agent last offseason out of the Dodgers' system, threw four hitless and scoreless innings on Tuesday to pick up his first Major League win. Barlow was effective again on Friday, throwing three innings in relief of Kennedy and giving up one run while striking out five.
UP NEXT Royals right-hander Jason Hammel (2-5, 5.23 ERA) will take the mound at 1:15 p.m. CT on Saturday for the middle game of this series against the A's at Kauffman Stadium. Hammel threw 5 1/3 scoreless innings on Sunday against the Rangers and he struck out a season-high 10. Former Royals righty Trevor Cahill (1-2, 2.25) will start for the A's.