On the disabled list since spring training, Prior is scheduled to make his Cubs season debut Friday against the Pirates.
"It hurts me more than anything to miss two months because you know you are letting your teammates down and your friends," Prior said Monday. "All I know is what I have in front of me and what I control. And that's the next four months."
After being sidelined with an inflamed right Achilles' tendon and sore right elbow, Prior was impressive in his third rehabilitation start Sunday when he allowed two runs and three hits while striking out 10 in 51/3 innings for Triple-A Iowa.
Now, he's ready to return to Wrigley Field for the first time since last season's dramatic Game 6 of the NL Championship Series.
"I'm not going to go out there and throw a complete game by any means on Friday," Prior said. "There will be some limitations and restrictions, but given the situation, I think it's the right time."
PETTITTE ON DL AGAIN: Astros left-hander Andy Pettitte went back on the 15-day disabled list with a strained muscle in his left forearm. Pettitte was hurt Wednesday while facing the Cubs and is eligible to activated June 11. Pettitte also was disabled from April 7-29.
GOING FOR THE CYCLE: Charlie Hamilton, a Red Sox fan who's cycling to every major-league ballpark this summer to raise money for cancer research, reached No. 7 on his list when he rolled into San Diego's Petco Park. The trip, which started at Atlanta's Turner Field and will end at Fenway Park, is scheduled for 11,000 miles.
BLUE JAYS: First baseman Carlos Delgado said a strained muscle in his right rib cage that knocked him from Saturday's game has bothered him for three weeks. He expects to return in two to four days.
DODGERS: Former Devil Rays left-hander Wilson Alvarez requested a return to the bullpen, saying he felt he could help the team while preserving his stamina by pitching in relief.
MARLINS: Right-hander Josh Beckett went on the 15-day disabled list with a blister on his right middle finger. Right-handed reliever Ben Howard was recalled from Triple-A Albuquerque. ... Five cars parked at Pro Player Stadium were destroyed by fire, officials said. No one was injured.
REDS: Third baseman Juan Castro left with a strained rib cage muscle and is day to day.
RED SOX: Manager Terry Francona was encouraged by the reports on shortstop Nomar Garciaparra's first Triple-A rehabilitation outing Sunday. "I talked to him and it surprised him how well he felt," Francona said. ... The team collected money to buy food and medicine for flooding victims in the Dominican Republic, home of stars Pedro Martinez, Manny Ramirez and David Ortiz. More than 1,000 have been killed by floods near the Haitian border, and thousands have been left homeless.