McCarthy earned his first win for New York with an impressive debut in pinstripes, and Brett Gardner drove in three runs from the leadoff spot to send the Yankees past the Reds 7-1 on Saturday.
Told his wife, Amanda, tweeted several wisecracks about all the highway congestion that delayed her arrival at the ballpark, McCarthy could only smile.
''If everybody isn't apprised of what she's doing every few minutes, God knows what would happen,'' he said.
Carlos Beltran homered, Kelly Johnson hit a two-run single and the Yankees ended Alfredo Simon's six-game winning streak in the right-hander's first outing since the All-Star game.
Derek Jeter had an RBI single, and New York won the first two in a three-game interleague series, leaving Cincinnati with five straight road losses.
''I think this is kind of a blip in the radar, but we certainly need to turn things around if we want to get that game tomorrow,'' Reds manager Bryan Price said.
Acquired from Arizona in a July 6 trade, McCarthy (1-0) struck out nine and walked none over six innings in his second start for New York and first at home. He said the Yankees have encouraged him to throw his cutter, a pitch he was instructed to scrap with the Diamondbacks.
''He's got top-of-the-rotation stuff, and we're really glad to have him,'' catcher Brian McCann said. ''He was doing whatever he wanted to on the mound today.''
McCarthy threw 71 of 99 pitches for strikes, improving to 3-0 with a 1.78 ERA in his last four outings after winning only once in his initial 16 starts this season.
''Actually, that was the frustrating part about the beginning part of the season is, I felt sharp,'' McCarthy said. ''I felt like everything was where I wanted it to be, I just wasn't doing everything I needed to to get the best out of it. So I felt like I've thrown better this year than any year in the past, it's just the results haven't followed.''
The right-hander was 3-10 with a 4.80 ERA for Arizona before New York obtained him to upgrade a rotation depleted by injuries to four starters. His first outing for the Yankees was a no-decision July 9 at Cleveland.
''You realize that you're putting the pinstripes on for the first time, but I try and wash all that away as much as I can and just focus on execution, focus on my routine, what I'm doing. All that stuff I can think about later,'' McCarthy said.
''I mean, you're pitching for the Yankees, and that's an opportunity no matter what the circumstances are. For me, it's at a point in my career where I want to be challenged. I really want to be in a pennant race. I wanted to be closer to the playoffs. I wanted to be in a market that is difficult. I wanted that kind of stuff to see if I could push myself to the next level, so it's a great opportunity in that sense.''
A converted reliever, the surprising Simon (12-4) is tied for the big league lead in wins - but he was betrayed Saturday by a Reds defense that entered with the highest fielding percentage and fewest errors in the majors.
The right-hander allowed four runs - two earned - and five hits in five innings, the first time he failed to finish six innings since going 3 2-3 in a 6-3 loss at Dodger Stadium on May 27. He went 6-0 with a 2.47 ERA in his next eight starts.
Chris Heisey homered for the Reds, struggling to mount much offense this weekend without injured boppers Joey Votto and Brandon Phillips.
Adam Warren, Shawn Kelley and Matt Thornton finished for the Yankees, who struck out 13. It was the first time they whiffed that many without issuing a walk since July 7, 2006, at Tampa Bay.
Cincinnati has struck out 23 times and walked once in the first two games of the series.
''We've got to pick it up a little bit,'' Todd Frazier said. ''That's not where we want to be.''
NOTES: Simon fell to 0-3 in seven games, including four starts, against the Yankees. ... McCarthy entered 0-2 with a 14.73 ERA in two starts and one relief appearance against Cincinnati. He had a 6.89 ERA in three previous starts at Yankee Stadium. ... Before the game, Frazier and Reds President of Baseball Operations Walt Jocketty gave Jeter framed jerseys autographed by the club's two captains, Dave Concepcion and Barry Larkin. Jeter also was presented with three photos taken June 3, 2003, the day he was named the 11th Yankees captain while the team was in Cincinnati. ... Looking to avoid a three-game sweep, Cincinnati sends another All-Star to the mound Sunday when RHP Johnny Cueto (10-6, 2.13 ERA) faces RHP Hiroki Kuroda (6-6, 4.10).