OAKLAND, Calif. -- It took him more than six weeks to work his way back to the major leagues, but Oakland As' right-hander Jesse Hahn made it just in time to face the Tampa Bay Rays, the team that drafted him in 2010, for the first time in his career on Sunday.

The Rays traded Hahn to San Diego with pitcher Alexander Torres to the Padres for pitchers Brad Boxberger, Matt Andriese and Matt Lollis and infielders Logan Forsythe and Maxx Tissenbaum on Jan. 22, 2014. The Padres traded Hahn to Oakland after the 2014 season.

Hahn will face Rays rookie right-hander Blake Snell, who was drafted by Tampa Bay in 2011, in the finale of the four-game series.

"There's a little bit of chip on my shoulder," Hahn said before the A's rallied for a 4-3 walk-off win in the ninth inning on Saturday night, their second straight walk-off win against the Rays. "I've always wanted to throw against them just because they were the first team to trade me and I have a lot of friends over there, a lot of guys I still talk to.

"It's going to be cool to do that. I finally see some of the younger guys I played with, seeing them up in the big leagues. I get to see them play in person which is going to be pretty cool.

"I know (infielder Tim) Beckham. I know Blake Snell. I've thrown against him. He's a good friend of mine. (Pitcher Alex) Colome. I pretty much know their whole team, all the guys that were Rays, drafted Rays, I pretty much know all of them."

Snell said he's "excited" to see Hahn pitch in person in the big leagues for the first time.

"It's going to be fun," Snell said. "I'm definitely looking forward to it. I haven't seen him pitch for a long time so I'm also interested to see how far he's come since high-A when I saw him last. I'm excited for it.

"We were never on the same team, but we were at extended spring (training) and instructional (league). We did have a good friendship."

Hahn was recalled from Triple-A Nashville on Sunday, 45 days after he had been sent down for the second time this season. Hahn went 7-4 with a 3.07 ERA for San Diego in 2014 and 6-6 with a 3.35 ERA last year in 16 starts for the A's before being shut down for the rest of the season with strained right forearm.

This year, he got off to a rough start with the A's and never found his pitching rhythm. He has gone 2-4 with a 6.49 ERA with Oakland and 1-5 with a 3.63 ERA with Nashville. Hahn said he finally got back on track in the final month or so with the Sounds.

"There was a month stretch where I was trying to figure things out," Hahn said. "Too many mechanical adjustments and stuff. I think it became a little mental. And I finally realized that there were just some small adjustments I needed to make and I was just pitching, keeping the ball down and throwing strikes.

"I (had gotten) away from throwing strikes and throwing my off-speed stuff for strikes. So I think this last month I've done a better job of that. Kind of got into a little rhythm, which I've been kind of looking for all year."

Hahn said the adjustments turned out to be "simple."

"Just me thinking, 'Hey, I need to throw strikes. I need to keep the ball down,'" he said. "I had to get some confidence back, but it actually ended up being that simple. Before, I was thinking too much. I was thinking, 'Oh, something's wrong. What's gone wrong, what do I need to fix?'

"I thought way too far into it. I think it was good to clear the mind and string some good starts together and get that rhythm back."

Snell has been in a good rhythm throughout much of his rookie season, going 2-4 with a 3.11 ERA. He's coming off the best start of the season on Tuesday against Colorado when he allowed one hit and struck out nine in six shutout innings in a 10-1 win.

"There's more that I'm looking for in myself," Snell said. "I definitely feel that I can get better, that I can learn. I got to stay hungry."

Rays manager Kevin Cash said he has been impressed by Snell's ability to "understand and work on the things that he needs to improve upon" and get better each start.

"The stuff, it's just very high-end type stuff, and he's going to be a very successful pitcher," Cash said. "It's just kind of honing all that into the strike zone and he's done that.

"He doesn't seem to get fazed by much out there, even when he had those outings when he couldn't find the strike zone. You didn't see a sense of panic on his part. Maybe some frustration but not panic, and I think that's a pretty good sign for a young pitcher."