Romero showed small signs of improvement in his third start before enduring a troublesome finish as the Buffalo Bisons defeated the Charlotte Knights 8-7 in 10 innings on Tuesday.
Romero walked all four batters he faced in the sixth inning — three of which scored — after he allowed just four hits and two walks through five innings. He did not factor into the decision as the Bisons overcame six late runs by Charlotte to win in extra innings.
"It's a frustrating way to end the night," said Romero, who left with a 7-2 lead. "I put the team into a hole there, but those first five innings were pretty good."
Romero admitted the battle right now is more in his mind.
"Nobody takes it harder than I do," he said. "I prepare every outing as hard as I can. It's tough to sleep at night. It's more mental than physical. It's like you're fighting yourself sometimes. I'm hoping I can overcome it quick."
The lefthander, optioned to Buffalo by the Toronto Blue Jays on May 10 after two ineffective major league starts, threw 47 of 96 pitches for strikes, a ratio hindered by recording only four strikes in his 20-pitch sixth inning.
There was no debate about whether Romero should have stayed in the game for the sixth inning.
"He was fine. He had a low pitch count," Buffalo manager Marty Brown said. "He's not a five-inning pitcher. He's experienced a tremendous amount of success at the major league level, and now he's battling himself too much."
Dustin McGowan, another erstwhile Toronto starter, made a rehab appearance and retired one of the five batters he faced in the seventh inning. He allowed three runs on two hits and two walks.
Romero has allowed 35 baserunners (18 hits and 17 walks) in 12 1-3 innings with Buffalo while striking out three. His triple-A earned-run average fell to 8.76.
Tuesday marked the second time in six pro starts this season that Romero logged at least five innings. He went seven frames in his season debut for single-A Dunedin on April 27.
Buffalo led 7-2 when Romero was replaced, but Romero struggled with inconsistency throughout, retiring the first two batters in four of the first five innings only to have the third batter reach base.
In the first inning, Romero's first walk was followed by a wild pitch and an RBI single.
In innings 2, 3 and 5, he yielded two-out doubles but rebounded to record the final out.
While Romero had a three-ball count on 11 of the 24 batters he faced, there was one facet of a classic Romero start: he recorded 10 outs via ground balls and only two via fly balls.
"It shows that my four-seamer and sinker were working," Romero said. "The big thing is to try to focus on the positives and not the negatives. As frustrating as it is, I have to get ready to work the next time."