Four months removed from shoulder surgery, Roy Halladay is still trying to recapture his Cy Young form.
The San Diego Padres' Tyson Ross, meanwhile, has been pitching at a very high level.
After getting pushed back due to the flu, Halladay takes the mound opposite Ross as the Phillies conclude a three-game set against the visiting Padres on Thursday night.
Originally scheduled to pitch Wednesday, Halladay (3-4, 7.19 ERA) was given an extra day to recuperate after battling the flu over the weekend.
"I think he lost a lot of strength for a couple days there," interim manager Ryne Sandberg told the team's official website. "He actually went home the first day with it. He's feeling much better."
The two-time Cy Young Award winner gets the ball for the first time since last Wednesday's 3-2 loss to Washington, when he permitted one run and three hits in six innings. Halladay, though, threw just 57 of his 99 pitches for strikes and issued five walks for the first time in six seasons.
"It took me a little bit to find the right balance, mechanically," he said. "That's going to be a little bit of a battle at times. I think if I put in the work and put in the time, I can have those results."
Still trying to build up his velocity, the right-hander is 1-0 with a 4.24 ERA in three starts since coming off the disabled list Aug. 25.
"I still feel like things can increase and, you know, the more I'm out there, the more I can gain," he said. "I don't anticipate jumping to 95 or anything or something like that, but I feel like command-wise, movement-wise, I feel like I can gain throughout the rest of the year."
Halladay is 3-2 with a 2.15 ERA versus San Diego (66-78).
He may need to be at his best against Ross (3-7, 2.79), who has thrived in nine starts since rejoining the Padres' rotation July 23. The right-hander has gone 3-3 with a 2.16 ERA over that stretch while striking out 63 in 58 1-3 innings.
"I've been feeling good, I'm having fun and learning every time out there," he told MLB's official website. "I'm definitely happy where things are."
Ross, winless in his last five starts, has received one run of support in each of those outings. He allowed three hits over seven scoreless innings Saturday in a 2-1 victory over Colorado.
"He's gotten better," Rockies shortstop Troy Tulowitzki said of Ross. "They've made some adjustments with him. The slider has been a plus pitch, and he's throwing the fastball on both sides of the plate. The slider has always been there. But his fastball command - and if you'd ask him, he'd say the same thing - has improved."
Ross threw 2 1-3 scoreless innings in two relief appearances versus Philadelphia this year.
The Phillies (67-78) are seeking a fifth victory in six games after winning 4-2 on Wednesday. Freddy Galvis and Jimmy Rollins went a combined 5 for 6 with two homers and three RBIs.
Galvis is 8 for 16 with two homers and four RBIs in his last four games.
San Diego's Tommy Medica homered in his big league debut Wednesday and Jedd Gyorko hit his 18th of the year, second-most among rookies.