Hammel has been stingy during four unbeaten starts at home for the Baltimore Orioles heading into Sunday's finale of this three-game set.
Lee (0-3, 2.92 ERA) remained winless despite a season-high 12 strikeouts as he gave up two runs over 7 2-3 innings in Tuesday's 2-1 loss to the Dodgers.
He's been working with a thin margin of error the whole year, with the majors' third-worst run support average at 2.23.
"Nothing I can do about it," Lee said. "All I can do is try to give the team a chance."
The left-hander owns baseball's fifth-best record in interleague history at 17-5, although he has lost his last two starts against the AL. Lee is 4-2 with a 4.25 ERA in seven career outings against the Orioles (33-26), limiting star center fielder Adam Jones to three hits in 14 at-bats.
Hammel (6-2, 2.97) figures to be formidable since he's 3-0 with a 1.73 ERA in four home outings. He yielded two runs over a season-low five innings Tuesday in an 8-6, 10-inning victory at Boston.
The right-hander is 1-2 with a 6.75 ERA in three career starts against the Phillies (29-32). Hunter Pence is 2 for 11 against him and Jimmy Rollins 3 for 11 while Shane Victorino has enjoyed more success by going 5 for 10.
These teams have split the first two games of this series, and the Orioles have again demonstrated why their bullpen is one of the majors' best with a 2.41 ERA. Their relievers have yielded one run over 10 innings in this series.
Baltimore's relievers limited Philadelphia to one run in five innings of Saturday's 6-4 win in 12 innings. That kept the game close for Jones to finish it with a two-run homer after he ended an 0-for-18 slump with a single in the ninth.
"One thing I'm not going to do is stop swinging the bat," Jones said. "It's part of who I am, it's the reason I got to the big leagues."
Buoyed by the handiwork of its relievers, Baltimore has won its last eight games in extra innings.
The Phillies have dropped seven of eight. They committed three errors in the fourth inning Saturday, giving them eight over their last four contests.
"I don't want to get in the habit where we're making mistakes,'' manager Charlie Manuel said.
Manuel's move of using Jim Thome as his designated hitter in this series has paid off. The veteran slugger is 5 for 9 and delivered his first 2012 homer and major league-best 60th in interleague play Saturday.
Some slumping Philadelphia hitters have started to get untracked. Pence is 5 for 9 in the series after entering in a 4-for-21 slide while Victorino is 4 for 9 with five RBIs after he came in mired in a 6-for-36 skid.
"Pence is a helluva player, Rollins, Victorino, they're some kind of club," Orioles manager Buck Showalter said.
Baltimore slugger Chris Davis is 3 for 8 with a homer and three RBIs in the series, and hitting .338 with five homers and 11 RBIs over his last 19 games.