HARRISON — Ryan Mallett’s broken foot may have been a result of previous stress-related injuries dating back as far as August, Arkansas Coach Bobby Petrino said Monday night.

Mallett broke the small toe in his left foot Feb. 17 during a change-of-direction drill on the University of Arkansas campus. The injury required surgery and a screw was inserted in the bone on Feb. 18. Mallett is expected to be fully recovered and cleared to return to drills in three to four months, the time frame presumably ending in July.

Mallett tweaked the same foot during two-a-day practices last August, Petrino said. The quarterback also hurt the outside of the left foot during a December practice in preparation for the Liberty Bowl in Fayetteville.

“He came out of a hand-off going to the right, booted out to his left and then kind of limped,” Petrino said before a speaking engagement at a booster club in Harrison on Monday night.

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Petrino was concerned Mallett’s cleats were hurting his feet. The shoes, provided by adidas, were changed out with a different pair after the incident in preparation for the Liberty Bowl, Petrino said.

“There was some stress involved when it finally did break,” Petrino said. “And we’re lucky it happened now. We're lucky it happened in the winter, when he’s got plenty of time to get the screw put in and heal properly.”

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Mallett set or tied 16 school records in his first year as Arkansas’ starting quarterback last fall and turned heads along the way. He threw for 3,624 yards and 30 touchdowns with 7 interceptions in leading Arkansas to an 8-5 record and win in the Liberty Bowl. He was a second-team selection on the All-SEC teams picked by the media and league’s coaches, and has already prompted Heisman Trophy talk among the national media this pre-season.

Mallett was scheduled to keep weight completely off the injured foot for four weeks after the surgery. Mallett was shown on a recent KFSM telecast resting his injured foot on a portable scooter while traveling on the UA campus. “He's done a really nice job of (staying off the foot),” Petrino said, “and then he’ll be in the boot for four more weeks, but I think he’s doing real well.”

Gaining unneeded weight while the junior-to-be recuperates should not be a problem, Petrino said. Mallett had weight issues when he arrived as a transfer from Michigan in January 2008. He weighed in at a lofty 265 pounds and was ordered immediately by the Arkansas coaching staff to drop weight. He lost more than 25 pounds within the next 18 months and has maintained a healthy lifestyle.

“It was kind of funny because, when he was in the hospital, I said, ‘Hey, Ryan, what do you want to eat? I'm going to get it for you,’” Petrino said. “And I was shocked at how he picked out a very good menu.”

Mallett has followed team nutritionist Kurt Schmidt’s dietary guidance during the healing process. Mallett has also worked his upper body and arms in the weight room and has done exercises with his right leg, such as squats, Petrino said.

The quarterback has also participated in throwing drills from a seated position with athletic trainers.

“What we really want him to work all through the summer and when we get into two-a-days, is working on his footwork and getting his feet properly set,” Petrino said. “Because when he has his feet set and his back foot is under his back hip, he can throw the ball as well as anybody.”

Meanwhile, redshirt sophomore Tyler Wilson has taken on a leadership role with Mallett sidelined, Petrino said. The backup has “done an excellent job,” and Petrino expects to give “a bunch of reps” to redshirt freshman Brandon Mitchell and newcomer Jacoby Walker at quarterback when spring practices kick off March 30.

Mallett’s broken foot isn’t the only injury he’s dealing with this offseason. Mallett had surgery in January on the labrum in his non-throwing shoulder, which was slightly torn.

“The shoulder is just about healed up and ready to go,” Petrino said. “Now it’s just a matter of getting the foot back.”

Mallett has been no stranger to injuries. He injured the ring finger on his throwing hand in June after a mishap in the weight room and was sidelined for several weeks. Mallett also dislocated the thumb on his throwing hand during spring drills in 2008, when he sat out a season after transferring from Michigan.