With the July 31 deadline for trades without waivers looking, Happ is considered a prime candidate to be dealt and the Yankees would be one of the interested teams, according to speculation.
The possibility of Severino (13-2, 1.98 ERA) and Happ (10-4, 4.03) soon becoming teammates adds another intriguing dimension to their matchup in the second game of a three-game series at the Rogers Centre.
The Blue Jays started the series with a 6-2 victory Friday night with Justin Smoak capping a five-run second inning with a three-run homer.
The Yankees (56-29) are 7-4 against the Blue Jays (41-46) in the season series so far, including a 4-3 record at the Rogers Centre as they complete their third and final series of the season there this weekend.
The win Friday ended the Blue Jays' four-game losing streak against the Yankees.
Severino is an obvious choice for the All-Star Game to be played at Washington's Nationals Park on July 17.
Happ is one of the few Blue Jays with a legitimate chance to go to the game.
Severino will be a leading candidate to win the American League Cy Young Award if he continues his current pace. He leads the majors in wins and is second in ERA.
The 24-year-old enters Saturday with a scoreless streak of 13 2/3 innings. He has allowed three runs or fewer in 15 straight starts, the longest such streak by a Yankees pitcher since Ron Guidry had a 15-game streak April 8-June 22, 1978. The only longer streak by a Yankee is 20 set by Russ Ford during the 1910 and 1911 seasons.
"I always feel great when Sevy's on the mound," Yankees manager Aaron Boone said. "The record in a lot of ways speaks for itself. The ability to get deep into games. He's been really good against the elite competition, it seems like, as well.
"He's putting himself in that conversation as one of the best in the game. There's no doubt about it."
Severino is 2-3 with a 4.12 ERA in nine career games (eight starts) against the Blue Jays and 2-0 with a 0.71 ERA in two starts against them this season. In five career starts at the Rogers Centre, he is 1-1 with a 2.81 ERA.
Happ had his worst start of the season Sunday when he allowed seven runs and 10 hits in 5 2/3 innings in a 9-1 loss to the Detroit Tigers.
He did not allow a run until the fifth when Nicholas Castellanos did most of the damage with a grand slam.
"I felt like I was a pitch away from getting out of it," Happ said after the game. "Again, I look at the hard-hit balls and there was two or three today. I didn't feel like I was in the middle of the zone getting hurt today, but it is what it is. It's not a pretty outing."
His only start against the Yankees this season was a loss on Opening Day, March 29, when he allowed three runs (two earned) in 4 2/3 innings as Severino picked up the win. In 17 career starts against the Yankees, he is 8-3 with a 3.53 ERA.
The Yankees have lost five of their past seven road games and are 23-16 in away games this season. They are 7-8 when visiting American League East cities this season.
The Blue Jays are 13-20 against AL East teams. They are 4-3 on their homestand and are 23-22 at home for the season.