Hunter began his Major League career with Texas in 2008 and was a member of the Rangers until being traded to Baltimore in a midseason deal last year.
He's struggled since joining the Orioles, but he has pitched well at Rangers Ballpark in Arlington throughout his career, going 14-4 with a 3.58 ERA. It will mark just the second time Hunter has faced his old club after losing to the Rangers in his only previous start against them in May.
Hunter has also turned it around as he has allowed three runs or fewer in three consecutive outings, while his ERA is almost two runs lower post All-Star break than it was in the first half.
"Sometimes old guys like me don't take that into perspective as much as we should," Orioles manager Buck Showalter said about Hunter and five of his teammates -- who all played with the Rangers last season -- returning to Texas. "It means something to them. They're very proud of their time here."
Rangers manager Ron Washington still thinks highly of Hunter.
"He certainly wasn't a guy we wanted to give up but to get what we needed, we had to give him up," Washington said. "He was in the learning process, and he's still learning. Once he figures it out, he's going to be a valuable piece. He looks really good.
"One thing is for sure, his mouth hasn't stopped running. He can talk. I didn't really expect that to change. But that's the competitor in him. He'll always be talking trash."
Hunter, who started, but lost, Game 4 of the 2010 World Series for the Rangers, will be opposed by former teammate Derek Holland, who pitched a masterpiece in Texas' Game 4 win in the 2011 World Series.
Holland joined the Rangers a year after Hunter made his debut after the two were Minor League teammates together in Texas' farm system. Like Hunter, Holland has struggled this season.
The lefty carries a 7-6 record and 4.98 ERA into the outing and has won just once over his past six starts. But he will look to get back on track against an Orioles team he is 2-1 with a 3.44 ERA against in four career outings.
Holland, who will also have the benefit of pitching on an extra day of rest, was cruising in his last outing before surrendering a sixth-inning two-run homer to Andruw Jones of the Yankees. He ended up walking away with his third consecutive no-decision.
"If I just keep doing what I'm doing, I'll be fine," Holland said. "The way I see it, is that it's one pitch. Everything else is fine. That one pitch I made to Andruw Jones last game is the only thing that hurt me. Other than that, I think I did a really good job of attacking the zone and going right after them."
The first-place Rangers have won nine of their past 11 games against Baltimore.
Orioles: Markakis enjoying top spot
Nick Markakis has been on a roll since assuming the leadoff spot in the Orioles' batting order in mid-July after coming off the disabled list with a right hamate bone fracture. Over 38 games, Markakis is batting .331 with five homers, 10 doubles, 26 runs scored, 16 RBIs and a .884 OPS.
Markakis, whose OPS is up nearly 100 points since batting leadoff for the first time in his career, had hit out of the three-hole in every game this season before landing on the shelf.
Outfielder Nate McLouth hit his first home run of the year in Tuesday's 5-3 victory. McLouth, who joined the Orioles on Aug. 4, has played in 50 games this season between the Orioles and Pirates. Although he is batting just .196 combined between the two teams, he has been Baltimore's No. 3 hitter for each of his past 10 games.
The 30-year-old is hitting .255 in 16 games with the Orioles, his first time playing in the American League.
Rangers: Soto starting to adjust to AL
Geovany Soto, who the Rangers acquired at the non-waiver Trade Deadline from the Cubs, has had mixed results since taking over as Texas' starting catcher after Mike Napoli was placed on the 15-day disabled list with a strained left quad Aug. 11. But recently, after amassing just one hit over his first 15 at-bats as the primary backstop, things are starting to click.
After hitting a two-run homer in the seventh inning of Tuesday's loss, Soto is batting .368 with one home run, three runs scored and five RBIs over his past six games.
David Murphy continues to tear the cover off the ball, and after a few more plate appearances, that will start to reflect in the AL leaderboards. Murphy is batting .478 with one homer, three doubles, four runs scored and six RBIs over his past six games to raise his average to .308, which is tops among Texas regulars.
The 30-year-old has already surpassed his RBI total from last season and matched his home run output, while sporting an impressive .877 OPS.
Holland, who has allowed at least one home run in six consecutive starts, has never surrendered a long ball to any current Orioles player, while holding them to a .408 OPS.
Adrian Beltre is batting .455 with one home run and a 1.273 OPS in 11 career at-bats against his former teammate Hunter.