Indeed, McCarthy was in rare form, and the A's couldn't recover in an eventual 7-2 loss to the Twins on Monday in the first of a three-game set that snapped their four-game winning streak.
Oakland is 12-12 over its last 24 contests, after going 16-2 over the previous 18, and sit in third place in the Wild Card race, a half game separating the green and gold from the second-place Orioles.
"It was a mess, from beginning to end," McCarthy said, not attempting to sugarcoat any part of his night. "I just mechanically felt completely out of whack with everything. That's pretty much what showed.
"I was horrible in the bullpen and had nothing at any point. It's been a long time since I had a day like this, where you just want a rewind button in the first inning and start all over. The first inning, I felt all right with [the first batter] in the box, and then I made a string of bad pitches and just got wild and lost all feel for everything. It was bad."
It marked the right-hander's shortest outing since Aug. 12 of last year, when he also went 3 1/3 innings vs. Texas. McCarthy surrendered 10 hits on this night, walking one and striking out two before passing the ball to lefty reliever Travis Blackley, who gave up one run over 5 2/3 innings -- the longest outing by an A's reliever this year.
"It just seemed like he was out of sync tonight," manager Bob Melvin said. "We haven't seen him pitch like that in a while. His ball-strike ratio was off early on, didn't have the command he normally does. He just didn't have the outing we're used to seeing from him."
Offensively, the A's couldn't pick up McCarthy, managing just two runs off Minnesota lefty Brian Duensing through six innings. Josh Donaldson's RBI double put Oakland on the board in the second, but Josh Reddick's RBI groundout one frame later marked the second and final run of the night.
"We kind of used the curveball to get ahead and get it over," Duensing said. "I don't know, if ever, I've had that much success with it late in the count. I thought we kept them off-balance and did a pretty good job with that tonight."
Oakland, in the end, made the biggest noise off the field, announcing in the seventh inning its acquisition of veteran shortstop Stephen Drew from the D-backs in exchange for Minor League infielder Sean Jamieson.
Drew is expected to report to the A's on Tuesday, at which point the club will announce a corresponding 40-man roster move. Several of the club's players expressed surprise when asked about the deal, not knowing what it could mean for a current teammate.
Count McCarthy among them. The pitcher was equally staggered by his performance.
"There's some days where you don't feel good and can battle through it, find some way to do it, but I wasn't able to do that today," he said. "I just felt like I was all over the place."