Happ, 35, is 10-5 this season with a 4.44 ERA, 1.18 WHIP and 115 strikeouts in 105.1 innings. He didn't exactly endear himself to suitors with his last performance, however, giving up six runs in 2.2 innings in an 8-5 loss to the Yankees on Saturday.
"I don't know, potentially subconsciously," he said when asked if the trade rumors were weighing him down, per Kevin Kernan of the New York Post. "I know these last two [starts] have not been really me or what I feel I'm known for, certainly not what I'm capable of. Having said that, I was ready to pitch. It didn't go my way. I have to find a way to stop that as soon as possible.
"I thought I was making some good pitches. They hit the two homers. It seems like right now every walk I give up comes around somehow or another."
As for any Cubs interest in Happ, the team has publicly maintained that it wants to give its in-house options a chance to get the job done.
"You're always looking to fortify and to add a little bit," president of baseball operations Theo Epstein said Friday, per Barry Rozner of the Daily Herald. "You always have Plan B and Plan C in case of injury or really bad performance, but there's no way we're going to go out and acquire starters the caliber of a locked-in Kyle Hendricks or a locked-in Jose Quintana.
"The majority of our answers lie within. That's how we're looking at it."
Outside of Jon Lester—and with Yu Darish still injured—the team's rotation has struggled. Hendricks is 1-4 with a 6.75 ERA in his last six starts, and Quintana has a 4.22 ERA. Mike Montgomery's ERA is 5.63 ERA over his past three starts, and Tyler Chatwood has given up 14 earned runs in his last two starts.
"We'll learn a lot more over the next few weeks," Epstein said. "There are a couple guys in some ruts that we expect to get out of and get locked in, but we need to see more."
Happ is also in a rut, having given up 20 earned runs in his past four starts and 13 in his past two. It's questionable if he would be enough of an upgrade for Chicago to justify surrendering assets.
But as the Cubs continue battling for a postseason berth—they are 1.5 games behind the Brewers in the National League Central—they may need to consider every move to ensure they play October baseball.