Sheets was tagged for his first five runs of the spring as the Giants batted around in the second inning of Milwaukee's 8-4 loss to San Francisco on Tuesday.
The right-hander said it reminded him of 2004, when he went 12-14 for the year but struck out 264 and had a 2.70 ERA.
"My best year, I probably had my worst spring," Sheets said. "I knew I was throwing the ball well, I know I'm throwing the ball well now. You kind of know when you're throwing the ball well."
Giants starter Matt Cain can sympathize with Sheets.
Cain got the second-lowest run support in the majors among qualifying pitchers last year and finished 7-16 with a 3.65 ERA, 10th-best in the NL.
It was similar to Sheets' year in '04 when his ERA was third-best in the NL, but Milwaukee was shut out in four of his starts and scored just one run in six more.
Cain was quickly down 2-0 in the first inning after hitting Rickie Weeks with a high fastball and allowing an RBI triple to Mike Cameron and a sacrifice fly to Prince Fielder.
Cain said it all could've been avoided had he found his location with two strikes on Weeks.
"Sometimes it's going to happen, but there's nothing worse than doing that with a two-strike count," Cain said. "I calmed back down and kind of got the ball down in the strike zone. I started to mix it up a little bit more and kept them off balance."
Cain struck out four and didn't allow any more runs, getting a pat and handshake from manager Bruce Bochy after finishing the fourth inning by striking out Jason Kendall.
Sheets, who gave up eight hits and two walks, allowed all his runs in the second inning with two outs after he got a break when Cain singled to center field and Cameron threw out Eliezer Alfonzo at the plate by several steps.
But the next five Giants all had hits, too, with the biggest blow being Aaron Rowand's two-run double.
"We kept the line moving well," Bochy said. "Everybody contributed."
Sheets said he was throwing all fastballs and changeups, but finally resorted to his big curveball to get out of the inning when he got Dan Ortmeier to ground out for the second time.
"It ain't no fun," Sheets said. "There ain't nothing fun about it."
Notes: Brewers RHP Yovani Gallardo is expected to pitch a simulated game Wednesday as he recovers from left knee surgery. "He's right on schedule," Brewers manager Ned Yost said. Yost said Gallardo will need to throw one or two more simulated games before he gets into an exhibition game. ... The Giants sent RHP Osiris Matos, RHP Kelvin Pichardo, OF John Bowker and OF Clay Timpner to their minor league camp. ... The Giants committed another error, their 22nd in 15 games.