CHICAGO -- Ryan Dempster is a jokester, often pulling pranks on his Cubs teammates. But he wasn't laughing Tuesday when he had to be scratched from his start because of a toe injury he suffered when he climbed over the fence in front of the Cubs' dugout at Wrigley Field after a game.

The best-case scenario is that Dempster (5-5, 4.09 ERA) will be sidelined three weeks, but he most likely will be out one month with a non-displaced fracture of his right big toe. He was placed on the 15-day disabled list Tuesday and Kevin Hart, optioned to Triple-A Iowa on Monday, was recalled and will start Wednesday. Carlos Zambrano filled in on short rest Tuesday night against the Atlanta Braves.

What happened?

"Sunday after the game, I was coming out of the dugout and I was stepping over the top of the railing and I caught my left foot on the rail as I was coming over," Dempster said. "It spun me around and slammed me into the ground. When I did it, I thought I ripped my nail back on my foot. Unfortunately, the result wasn't funny."

Cubs first baseman Derrek Lee was laughing when he saw Dempster's awkward fall.

"I'm sure it looked hysterical from his angle," Dempster said. "The unfortunate part is my foot, because of the way it hit, came down straight into the ground. My toenail was ripped back and bleeding."

The plan on Tuesday was to get a shot to ease the pain. But X-rays revealed the fracture.

"I'll just drink some Incredible Hulk juice," Dempster said. "It's a weird thing."

In his last start Thursday against the Milwaukee Brewers, Dempster took a ball off his shin and kick-saved one to himself. He also took a ball off his face in batting practice recently and was fine.

"I'd like to have some nice gratifying story, like I broke up a double play or something and saved the game, but I don't," he said. "I wasn't going to make up a story because somebody would find a video. ... That's what I get for making fun of guys who go on the DL for burning their faces in a suntan booth."

He'll get X-rays again before the Cubs go to Washington for the first series after the All-Star break. In the meantime, Dempster will get treatment and keep his foot elevated. Dempster, who could barely walk into the interview room to talk about the accident, planned on pitching Tuesday, but said the risk wasn't worth the reward.

This is not one of those Cubby occurrences.

"It's a coincidence," Dempster said.

Did Lee apologize for laughing?

"No, I think he's still laughing at me," Dempster said.

Lee chose not to talk prior to Tuesday's game about the incident. Lou Piniella found out when he got a phone call at lunch.

"Well, we were healthy for a day," said Piniella, who got Aramis Ramirez, Reed Johnson and Angel Guzman back on Monday. "We had a pretty good idea this was more than a stub or a bruise or strain."

There aren't many witnesses to the accident.

"I didn't see it, no," Piniella said. "I went up the stairs. I couldn't skip the fence."