When the Chicago Cubs start spring training games, Mark Prior will be resting his right foot instead of firing fastballs.

The hard-throwing right-hander will be out five to 10 days because of an inflamed Achilles tendon, soreness he first felt last September.

“When I started working out again in January on the mound, it started back up, and I got here and it got inflamed,” Prior said Monday in Mesa, Ariz.

An MRI showed no structural damage or tear. Both Prior and Cubs trainer Dave Groeschner said the 23-year-old would be ready for opening day.

But it could be nearly two weeks before he can pitch in an exhibition game. After he is cleared to throw again, Prior will have to build his arm strength back up. The Cubs begin exhibition play Thursday.

“It’s early in the spring, and we can nip this in the bud and make sure he’s ready for the season,” Groeschner said.

In Vero Beach, Fla., Jose Canseco struggled through an open tryout with the Los Angeles Dodgers and looked nothing like the slugger who intimidated opposing pitchers in the late 1980s and ’90s.

Matt Slater, the Dodgers’ director of professional scouting, said Canseco was told several days ago there was a 99 percent chance the team wouldn’t sign him.

“This is probably going to be my last attempt — see you in the movies,” Canseco told reporters afterward as he signed autographs.

In Scottsdale, Ariz., Giants owner Peter Magowan said he thought the deal that sent Alex Rodriguez to the New York Yankees was bad for baseball.

“The Rodriguez trade moves us back to where we’re escaping. The team with the highest payroll can add the highest-salaried player. It’s good that A-Rod is playing in a big market, but it should be another big market,” Magowan said.

“I think all of us in baseball would prefer to get a salary cap if we could. The Yankees are probably the only ballclub that would not want to have one. They have a payroll of $185 million. We’ll probably start the season at $80 million,” he said.

In Phoenix, Athletics pitchers Rich Harden and Chad Bradford each took a step forward in returning from minor injuries.

Harden, who said he hurt his left (non-throwing) shoulder turning off an alarm clock, threw 40 pitches on the side. Bradford, recovering from back spasms, played catch for the first time in more than a week.

In Tampa, Fla., Yankees right-hander Mike Mussina was scratched from his first spring training start following the death of his father-in-law.

Mussina was scheduled to pitch the spring opener Thursday against Philadelphia. He is the probable starter for the regular-season opener March 30 in Tokyo against Tampa Bay.

Also, New York center fielder Bernie Williams was back at spring training, one day after being released from the hospital. He had his appendix removed Thursday.

In Tucson, Ariz., White Sox reliever Shingo Takatsu, Japan’s career saves leader, threw an inning of relief in an intrasquad game and flashed a tricky changeup.

“Sometimes it kind of looks like it can defy a little gravity sometimes,” pitching coach Don Cooper said.

In Port St. Lucie, Fla., the New York Mets got a glimpse of what they hope will be a promising future when talented youngsters Jose Reyes and David Wright each hit a two-run homer in an intrasquad game.