The Phillies announced a change in their starting rotation because Cole Hamels has the flu.

Hamels, who was supposed to start Sunday against Washington, has been pushed back to Tuesday, when he will face the visiting Toronto Blue Jays.

Roberto Hernandez, who was slated to start Tuesday, will pitch Sunday.

Kyle Kendrick will remain the starter Monday against Toronto.

Manager Ryne Sandberg said Hamels reported that he didn't feel well Friday. At that time, Hernandez was available for relief duty, but the Phillies held him back.

"We stayed away from using him, knowing how Cole was feeling [Friday] and wanting to see how Cole was [Saturday]," Sandberg said before the game Saturday against the visiting Nationals. "[Hernandez] is good to go."

Hernandez's last start was April 25 in a 5-4 loss at Arizona. He allowed four earned runs in six innings and took the loss.

Hernandez also pitched one-third of an inning in relief during a 6-1 loss Tuesday to the New York Mets.

That was Hamels' last outing, in which he allowed six runs (all earned) in 42/3 innings. Hamels, who didn't make his first start until April 23 because of biceps tendinitis, is 0-2 with a 6.75 ERA in two starts.

Farmhands of the month

Reading outfielder Cam Perkins and righthander Ken Giles were named the Phillies' minor-league player and pitcher of the month for April.

Perkins batted .382 with two home runs, 14 RBIs, and a 1.023 on-base-plus- slugging-percentage for April. Giles, owner of a 100-m.p.h. fastball, had a 1.38 ERA and converted seven saves in eight chances.

Staying sharp

Kendrick, who had his start rained out Wednesday and then was pushed back to Monday so the Phillies' top three starters could face Washington (before Hamels came down with the flu), has not pitched since April 24 in a 7-3 win at the Los Angeles Dodgers.

"I have done it before, going back and forth, so this is nothing new," Kendrick said about moving in the rotation. "I threw a bullpen session [Friday], and I have to stay on top of my arm exercises."

Lidge's observation

Brad Lidge threw out the first ball before Saturday's game. Lidge will always be known for converting all 48 save opportunities, including seven in the playoffs, during the Phillies' 2008 World Series championship season.

Although the Phillies entered Saturday with six blown saves, Lidge believes the bullpen will turn it around. He is particularly high on Jake Diekman, who entered the game with a 6.75 ERA.

"He is a guy who can potentially dominate in this league," Lidge said.