The most important aspect of Happ's first month for the Yankees is his 5-0 record in his first five starts.
Happ attempts to make it six straight wins Thursday night when the Yankees host the Detroit Tigers in the opener of a four-game series.
The left-hander is 5-0 with a 2.37 ERA since joining New York in a trade with the Toronto Blue Jays on July 26. Happ is 15-6 with a 3.80 ERA overall this season, and in his four starts immediately before the trade, he was 0-3 with a 7.41 ERA.
"I don't know that he's gotten better because I've always had a high opinion of him," Yankees manager Aaron Boone said. "This is a guy I was really hoping we would be able to get. So, him coming here and having success, I kind of expected it just because of the high regard I have for him as a pitcher, what I believe he is."
Happ began his tenure with New York by beating the Kansas City Royals on July 29 and has pitched into the sixth in each outing. He is the first pitcher to start and win each of his first five appearances for the Yankees since Bob Turley in 1955.
Happ's last start was in the first game of Saturday's doubleheader in Baltimore. After laboring in the second inning at times, he ended up allowing two runs on five hits in six innings of a 10-3 win.
"He's a guy with quality stuff, just a real simple athletic, repeatable delivery, a really good demeanor on the mound," Boone said. "Whether he makes a great pitch or not, he's able to stay in rhythm and turn the page on that pitch and get after it."
Happ has been traded four times in midseason. In those post-trade appearances, he is 20-8 with a 3.14 ERA in 39 games (35 starts)
His strong start as a Yankee gives Happ a chance to become the sixth 16-game winner in the majors.
He is 3-2 with a 4.83 ERA in 10 appearances (nine starts) against the Tigers. Happ faced Detroit twice this season while with Toronto and went 0-1, allowing 11 runs on 15 hits in 10 2/3 innings.
The Yankees are hoping to rebound after dropping two of three to the Chicago White Sox. They ended the series by taking a 4-1 loss on Wednesday, two nights after absorbing a 6-2 defeat.
"The losses stink," Boone said. "There's nothing better than shaking hands at the end of the day. That's what we pour everything into, but as far as who it's against, I don't really care. It's let's get after it and we got to get after the Tigers coming in tomorrow."
Giancarlo Stanton remains stuck on 299 career homers and went 0-for-3 Wednesday. He has two hits in his last 26 at-bats, spanning his last seven games
New York is 16-7 in its last 23 games since it was swept in a four-game series at Fenway Park Aug. 2-5.
Detroit heads to New York on a five-game losing streak after getting held to three hits and striking out 11 times in Wednesday's 9-2 loss at Kansas City. During this skid, the Tigers are hitting .222 (30-for-135) while getting outscored 34-10.
The Tigers also are 1-11 in their last 12 road games, and their 19-46 road record is the second-worst in the majors.
"We haven't played well on the road and I don't know why," Detroit manager Ron Gardenhire told reporters. "Nothing much good has happened for us on the road and we have to figure that out. It's just a battle right now."
The Tigers (53-80) are tied with the White Sox for third place in the AL Central. While the White Sox are playing better, Detroit has dropped 18 of its last 24 games and has been held to three runs or fewer 14 times in that stretch.
"It's frustrating to lose," catcher James McCann said. "No one likes to lose. No one shows up to lose."
Detroit may be without shortstop Jose Iglesias, who exited Wednesday's game with a lower abdominal strain. He is expected to undergo an MRI exam on Thursday in New York.
The Yankees are 26-11 in games started by left-handers and will face Detroit's Francisco Liriano on Thursday. Liriano (3-9, 4.82 ERA) is 0-8 in his last 16 appearances since April 28.
Liriano dropped his fourth straight start on Aug. 22 when he allowed four runs on seven hits in 5 1/3 innings against the Chicago Cubs.
He is among those who have cleared waivers and Thursday could be his last start by Friday's deadline to make waiver deals.
Liriano is 4-4 with a 3.34 ERA in 12 appearances (10 starts) against New York. He is 0-3 with a 5.48 ERA in five career appearances (four starts) at Yankee Stadium.