Porter may have a difficult time sending the left-hander back down if he can put together a second straight solid outing.
Oberholtzer takes the hill Thursday night as the last-place Astros look to prevent the Los Angeles Angels from winning seven in a row at home for the first time in nearly eight years.
Despite being on his third stint in the majors this season, Oberholtzer (2-6, 4.40 ERA) has remained positive and done his best to prove he belongs in Houston's rotation.
He was impressive in his first big league outing in nearly a month Saturday, allowing one run in 6 1-3 innings and leaving with a one-run lead in Houston's 4-3 loss to Detroit.
"He's handled it tremendously each time he's had to go back to the minor leagues," Porter told MLB's official website. "He understands the situation we're in. He's kept himself in the right frame of mind every time to be able to come up here and give us quality starts."
There's a chance Oberholtzer could be sent back to the minors after this outing. His last start came due to the late scratch of Dallas Keuchel, who will start Friday.
Oberholtzer has never faced the Angels and will try to help keep them from dealing the Astros (36-50) a fourth consecutive defeat.
Los Angeles (47-36) split a six-game trip with a 3-2 loss to the Chicago White Sox on a walkoff single in the ninth Wednesday. Josh Hamilton made a home run-saving grab in the field and tied the game in the eighth with a solo shot for his second homer of the series.
The Angels return home having won 12 of 13 in Los Angeles and seek their first seven-game win streak in their ballpark since August 2006.
Matt Shoemaker (5-2, 4.50) will take the mound looking to bounce back the worst outing of his career. Shoemaker went 5-0 with a 3.00 ERA in his first seven starts before allowing eight runs and 11 hits in four innings of Friday's 8-6 loss to Kansas City.
The right-hander won his previous two outings while giving up three runs and striking out 16 in 15 2-3 innings.
"It was definitely not fun," Shoemaker said. "It's going to make me tougher, not that I wasn't, but you learn from it."
Shoemaker also hasn't been very successful in two relief appearances against Houston this season, giving up four runs on a two-run homer and a pair of solo shots over 3 1-3 innings.
Chris Carter homered off Shoemaker on June 3, but he's 3 for 38 (.079) over his last 12 games and was benched in favor of rookie Kike Hernandez for Wednesday's 5-2 loss to Seattle.
Hernandez made his major league debut Tuesday and went 2 for 2 with an RBI in relief of Jose Altuve during a 13-2 blowout loss. He hit his first major league homer the following day, giving Porter the confidence to stick with him.
"He's swinging a good bat and that's why he was in the lineup (Wednesday) and he'll be in the lineup (Thursday)," Porter said of Hernandez.
Hamilton has swung the bat well against the Astros this season, hitting .400 with three homers and seven RBIs in seven meetings.