After giving up two runs in a total of 13 1/3 innings against the Padres and Rockies to begin the season, the D-backs right-hander allowed seven runs in just 5 2/3 innings for the loss.
Cahill will try to get back to his winning ways and forget about that last start when he faces the Phillies on Wednesday in the series finale at Chase Field.
"I was thinking I had to make quality pitches, and I'd leave a ball over the plate instead of relaxing," said Cahill after his last start.
He'll have a tough assignment matched up against Phillies left-hander Cole Hamels.
While Hamels battled in his last start against the Padres, he came away with the win after allowing one run on six hits in six innings of work, improving to 2-1 on the season with a 2.95 ERA.
He also struck out four and walked one, but he was called for two balks. After the contest, Hamels was just happy to get the win.
"It's one of those days where I wasn't able to really locate with too many pitches," Hamels said. "You just keep battling, and fortunately [with] the ballpark you can get away with throwing some pitches down the middle and trying to let them put it in play."
Phillies: Pence in lineup after MRI
After Hunter Pence had a precautionary MRI done on his left shoulder on Tuesday, he was back in the Phillies' lineup against the D-backs and hit a two-run homer.
"They honestly did not expect me to be this good today," Pence said before Tuesday night's game. "I typically heal really fast. I don't know what it is, but I just do. ... I'm able to move it and I'm able to play, and there's no danger."
Ty Wigginton started at third base Tuesday against the D-backs, putting Placido Polanco on the bench for the third time in seven games.
D-backs: Gibson not committing to Miley
Despite Wade Miley throwing six shutout innings against the Phillies on Monday, D-backs manager Kirk Gibson isn't ready to say if the left-hander will get another start.
"We haven't made that decision yet," Gibson said. "This isn't the time to speculate, it depends on what happens this week."
Miley won't pitch the next few days and the team has an off-day on Thursday, so the next scheduled game for his spot in the rotation would be on Sunday at Miami.
With Miley resting after starting Monday and Joe Paterson struggling to record outs, the D-backs made two roster moves Tuesday to strengthen their bullpen. The club recalled right-hander Joe Martinez and lefty Mike Zagurski from Triple-A Reno, while optioning Paterson and designating for assignment reliever Jonathan Albaladejo, who was just called up Saturday.
The Phillies are 4-5 against National League West opponents this season after going 23-9 against them in 2011.
The D-backs are 27-10 in their last 37 home games.
Phillies left-hander Cliff Lee played catch for the second consecutive day. He is on the 15-day disabled list because of a strained left oblique.