ARLINGTON -- The Rangers have been shuttling relievers to and from Triple-A Nashville all season long. Left-hander Kyle Bird has made the round trip five different times.

Brett Martin made it once but appears to have graduated. One of the bright spots coming out of the Rangers pitching staff this season is Martin establishing himself as a left-handed weapon out of the bullpen.

Martin threw two scoreless innings in the Rangers’ 5-4 win over the Tigers on Saturday night; the Tigers scored an unearned run during his two-thirds of an inning in Sunday afternoon’s 9-4 win. Martin now has a 2.53 ERA, 0.94 WHIP and 12.66 strikeouts per nine innings in his last eight games.

“It’s impressive talking to that kid,” manager Chris Woodward said. “When he competes out there, he’s fearless, he doesn’t get rattled. He is so evolved in that way. That’s why I am so impressed not only with his success but who he is and where he is from an emotional standpoint.”

The Rangers moved Martin to the bullpen last year at Double-A Frisco almost out of desperation. He was 1-9 with an 8.61 ERA in 15 starts when the Rangers decided to move him to the bullpen after the Texas League All-Star Game.

“The year I was having last year, I was like, I’ll try anything at this point,” Martin said. “Get off the mound more, get more reps at game speed and see if I could figure something out.”

He did. Martin made 14 appearances out of the bullpen with a 4.28 ERA, 1.39 WHIP and 10.9 strikeouts per nine innings. That kept him on the 40-man roster and brought him to Major League Spring Training where he captured the attention of Woodward and the new coaching staff.

“I think struggling was the best thing for me,” Martin said. “If I didn’t struggle like I did, I wouldn’t have learned what I did. Just to trust myself. If I fell behind 2-0, I’d have to throw a fastball to get back in the count. They knew it, everybody in the ballpark knew that, instead of trusting my slider, curveball or changeup to get back in the count. I started doubting myself. When I started trusting myself, everything else took care of itself.”

Martin still has the three-pitch mix needed to start including a fastball that averages 93.7 mph. He has also learned to elevate the fastball when needed rather than pound it low in the strike zone.

That raises a question: Would the Rangers consider moving him back to the rotation in the future?

“It has come up in discussions, for sure, just because [of] how well he is doing,” Woodward said. “Obviously, right now I really like where he’s at. He is a multiple-inning guy. That question is never going to go away as long as he keeps having success. It may be something we end up doing. I don’t know. There is a lot of factors in that. It’s definitely talked about.”

Boyd baffled by Odor

Tigers pitcher Matthew Boyd said he was surprised Rougned Odor reacted the way he did after getting hit by a pitch in the sixth inning of Saturday’s game. Odor took a fastball in the back, then glared out at Boyd and started yelling at him.

"It was a 3-2 count, and we were both battling,” Boyd said. “He just looked at me, so I asked him what he was looking at. I'm not trying to hit a guy like that, [who] has an average off me of, like, .192 or something like that. He's not a guy you really want to give a free pass by any means."

Home plate umpire Eric Cooper stepped in and escorted Odor to first base.

“He was telling [me] he was not trying to hit me,” Odor said. “That it was a 3-2 count. That’s all.”

Rangers beat

• Left-hander Kolby Allard, acquired from the Braves on Tuesday for reliever Chris Martin, made his first start for Nashville on Saturday and pitched five scoreless innings against Albuquerque. He allowed four hits, walked two and struck out eight.

• Odor’s home run on Saturday was the 20th of the season. It’s the third time in his career he has hit 20-plus home runs in a season, tying Ian Kinsler for the most by a Rangers second baseman.

• As of Sunday, the Rangers six Minor League teams had a .572 winning percentage for the season, the highest of any organization.