An ankle injury has forced Kenny Chesney [ tickets ] to delay the first four dates of his "Somewhere in the Sun Tour," which also features Gretchen Wilson and Uncle Kracker.

Originally scheduled to kick off March 10 with a two-night stand at Green Bay, WI's Resch Center, the run is now set to launch with a previously scheduled March 17 stop in Tupelo, MS. Also postponed are a March 12 show in Saint Paul, MN, which is now set for March 26; and a March 13 show in Fargo, ND, which will take place March 25.

"I know the fans in Green Bay, Fargo and St. Paul are gonna be disappointed," Chesney said in a statement. "But they're not half as disappointed as I am about not being there. I was very excited about kicking off this tour, but hopefully this will only be a short setback ... and you can bet I'm gonna be real serious about my physical therapy 'cause I wanna be in fighting shape and good to go for the shows."

Chesney's doctor said that the singer "has a severe ligament injury to his right ankle," according to a press release.

"He's going to have to undergo extensive and immediate physical therapy and rehab," Dr. Burton Elrod said. "He's going to have to play sore--with his ankle taped or with a brace under his boot, but he's like an athlete who can perform with some pain. He wants to get back out there and because he's so athletic and in such good shape, he is going to heal a lot better and quicker than most people."

"We were so in the zone and ready to rock," Chesney added. "And when you're ready to get out there and play for the fans, this is the last place you want to find yourself. My ankle looks like a softball--and I'm keeping it elevated."

Despite the delay in launching his tour, Chesney is still slated to give a March 9 performance at the Houston Livestock & Rodeo. That set will not require "the same level of physical intensity that Chesney's own stage does," according to a press release.

Meanwhile, new to Chesney's itinerary are two-night stands in Columbus, OH; and Las Vegas; as well as one-off stops in Oakland, CA; and Milwaukee. Also added to the schedule is a second night at Omaha's Qwest Center. Details are shown below.

"We wanna play for everyone who wants to come rock with us," the singer said. "I hate hearing that people waited overnight for tickets, then couldn't get any ... So, we're adding shows where we're able to. The thing is trying to have those adjacent dates available."

Dates for the tour's second leg are expected to surface this week.

The tour backs Chesney's latest album, "Be As You Are: Songs from an Old Blue Chair," which hit stores in January and debuted at No. 1 on The Billboard 200 album chart. The set follows last year's "When the Sun Goes Down," which, with sales of more than 3 million copies, was the No. 4 top-selling album of 2004.