The uncertainty about A.J. Barker's ankle injury is finally over, but it's an unsatisfying conclusion for the Gophers. Barker, the team's leading receiver, quit the team on Sunday, and he used a 4,000-word public denunciation of coach Jerry Kill to do so.

"I'm done with you for good," Barker wrote in an open letter posted on a tumblr.com blog. "In light of that pathetic, manipulative display of rage and love you put on this past Thursday, I have come to the decision, with the guidance of my parents and my closest friends, that my time on this team has come to an end."

The 21-year-old DeLaSalle High School graduate said he intends to transfer to another school for his senior year, and because of his status as an unrecruited walk-on, he believes NCAA rules requiring transfers within Division I to sit out a season will not apply.

Kill tried to contact Barker, who has not played since suffering an ankle injury during the Gophers' 44-28 victory over Purdue on Oct. 27, after receiving the letter via e-mail on Sunday, according to a statement released Sunday night by athletic director Norwood Teague, but was unable to do so.

"We understand A.J.'s frustration with his injury, and we regret that he has chosen to leave the team on these terms," Teague's statement said. "Our concern first and foremost is student athletes, and we wish A.J. well."

Teague's statement was the only response from the university.

Star Tribune file, Star Tribune
A.J. Barker (82) was the Gophers’ leading receiver when he was injured in a victory over Purdue on Oct. 27.

Barker's departure removes this year's best receiver from the Gophers offense for good. The former All-Metro prep player caught 30 passes, seven for touchdowns, before being injured, and even after missing three games, those numbers still lead the Gophers receiving corps by far. Barker's 72.1-yard average would rank third in the Big Ten if he had enough games to qualify for the league leaders.

But the St. Paul native, who joined the team in 2009 and made only one catch before emerging this season, was confronted by Kill at the team's practice on Thursday, Barker said, after the coach became angry about how his sore ankle was being treated. An MRI taken Wednesday revealed torn ligaments in his foot, Barker said.

According to Barker, however, it wasn't Kill's angry lecture that riled him. "I've been screamed at before by coaches," Barker said Sunday in a telephone interview. "What bothered me was, when practice was over and it was just the two of us, he spent 20 minutes talking about how he admired me, talking about [his] love for me as a person. To me, he was just being a hypocrite, because he had made it clear when he was screaming a few minutes earlier that he really had something against me."

Still, it's clear from his lengthy, indignant post that Kill's criticism stung the receiver. "I will not accept your ruthless attempt to degrade and belittle me," Barker wrote.

Kill had warned him that he would "have to work your way from the bottom up" once he was healthy enough to play, Barker said in his post. "I might have been back by bowl time," he said Sunday night, "but [Kill] made it clear I wasn't going to play ... that he didn't need me and the team didn't need me."

Thursday's confrontation, which began while Kill was standing 40 yards away, according to Barker, was prompted when Kill learned from the team's athletic trainer that the receiver was making his own choices about his treatment rather than following the trainer's direction. After what he described as a 20-minute tirade, Barker said, Kill called him over after practice and tried to connect with him in a more calm, supportive way.

Barker did not travel with the Gophers a week ago to Illinois or last weekend to Nebraska. And Sunday afternoon, he announced, first via Twitter -- "Well, its official. I am done playing football for the University of Minnesota and I will be looking to transfer next season for my final yr," his tweet read -- and then via his Tumblr post, which has an irate tone and is sprinkled with curse words. Barker also claimed in it that an assistant coach once used a slur to refer to him.

In Barker's absence, the Gophers will rely upon a pair of injury-plagued seniors, MarQueis Gray and Brandon Green; freshman Andre McDonald; transfer Isaac Fruechte; and sophomore Devin Crawford-Tufts. The Gophers receiving corps was thinned even further Saturday, when Marcus Jones suffered what appeared to be a knee injury.

Star Tribune columnist Patrick Reusse contributed to this report.