By Annie Ross

Phillies fans should understand one thing about Darin Ruf:

He’s a deep thinker!

Ruf hit a two-run homer in the first inning to help the Phillies beat the Pittsburgh Pirates 4-2 yesterday.

The 29-year-old Ruf came into camp competing with former MVP Ryan Howard for regular playing time at first base.

Phillies manager Pete Mackanin has talked about platooning the two, and yesterday’s game could strengthen that standpoint: the righty-hitting Ruf’s home run came off Pittsburgh lefty Jonathon Niese.

”It was a cutter,” said Niese, who chatted with Ruf after reaching on a single in the third inning. ”I told him when I got on first base that I’m never throwing it to him again. He’s punished it every time I’ve thrown it to him.”

Ruf has three homers and a .294 average for his career in the regular season against Niese, a former Met.

”I know I’ve hit a couple of home runs off him in the last couple of years,” Ruf said with a laugh. ”I think he’s trying to get in my head.”

Ruf hit .371 against left-handers last season, and his 1.107 OPS against lefties was best in the National League among players with at least 100 plate appearances.

Cesar Hernandez, who replaced Chase Utley at second base last season, doubled the Phillies lead with a two-run triple in the second inning. Hernandez, 26, took over as the team’s regular at the keystone when Utley was injured in June and then traded to the Dodgers.

Howard, meanwhile, hasn’t played in a game since March 4. He was sent away from camp on Saturday with a head cold that’s been spreading through the Phillies clubhouse in the last two weeks.