"It has been a little while since we've been in a situation like this," said Lyon, who posted a 3.25 ERA in 36 innings for Houston. "So I'm excited, I'm excited to get out there and obviously see what I can do and get that adrenaline flowing.
"It's a little bit different of an adrenaline flow when you have the game on the line in situations where teams are just trying to get a win. I'm excited for it, I can't wait to get out there."
Happ is expected to eventually join the Blue Jays' rotation, but for now, he will pitch in relief. Manager John Farrell wants to go through another turn in the rotation before making any decisions about who Happ could possibly replace in the starting five.
The 29-year-old hasn't pitched in relief since 2009, and while starting is his preferred spot, Happ is willing to accept whatever role the club wants to put him in.
"That's what I'm most comfortable with," said Happ, who is 7-9 with a 4.83 ERA in 18 starts this year. "It's what I've done the most. I don't want to make any waves, cause any waves, but that's where I see myself being, and hopefully, they do, too, at some point."
For Lyon, the trade marked a return to the franchise that selected him in the 14th round of the 1999 First-Year Player Draft. The Utah native proceeded to make 21 starts for the Blue Jays in 2001-02 before he was claimed off waivers by Boston.
Since that time, Lyon has spent his entire career out of the bullpen where he owns a career 30-37 record with a 3.88 ERA and 353 strikeouts in 505 2/3 innings.
"It makes it easier for me," Lyon said of going back to Toronto. "Obviously feeling for J.A. right now, I don't think he knows many people around here.
"At least, I can come in here, I can see a few faces that I've seen in the past and it does make it a little bit easier. But any time you have to switch teams and go through the whole meeting new teammates, it's uncomfortable for a few days. But once the game starts, you're playing baseball, you might just have a different uniform on. It will be a lot easier once the game starts for everybody in this situation."