The 58-year-old Porter is now a probation officer for Ramsey County, but it was unclear whether the beating was connected to his job. Police said no one had been arrested and they had no suspects.
Few details about his condition or where he was hospitalized were released at the request of his family and out of concern for Porter's well-being, St. Paul police spokesman Tom Walsh said Tuesday. Authorities were not ruling out the possibility he could be attacked again.
According to police, Porter went missing about 9 p.m. Friday after leaving his house in St. Paul. His car was found Sunday, and police asked for the public's help in finding him.
"We want very much to reconstruct the several hours after 9 o'clock on Friday," Walsh said. "Where he went, who he spoke with."
Minneapolis police received a call about 5:30 a.m. Saturday that a person was found lying in an alley on the north side of town, according to police Lt. Amelia Huffman. The man didn't have any identification on him and was "clearly suffering from some injuries." He appeared to have been assaulted, but was not able to tell police anything.
The man, later identified as Porter, was entered into the computer system as an unknown assault victim and was taken by ambulance to the hospital.
"He needed immediate medical attention," Huffman said. "No one knew at that point that it was Mr. Porter."
Porter is one of the greatest players in Villanova's rich basketball history. He led the Wildcats to the 1971 NCAA championship game, where they lost to UCLA 68-62. He was voted the tournament's outstanding player, an honor later vacated because he had been dealing with an agent before the season ended. Villanova's 1971 runner-up title also was vacated.
In his career in 1968-71, he averaged 22.8 points and 14.8 rebounds. In 1997, Villanova retired Porter's No. 54 jersey.
Porter visited with the Wildcats when they were in Minneapolis for the 2006 NCAA tournament regional games and struck up a friendship with Villanova standout guard Randy Foye. Foye, who now plays for the Timberwolves, said Porter came to watch him play a few times last season and was shocked at the news.
"I just wish him the best," said Foye, who was at the NBA draft lottery in New Jersey. "It's just a shame what happened."
Porter was drafted by Chicago in 1971, the 32nd overall pick, and spent three seasons with the Bulls before playing with the New York Knicks and the Detroit Pistons. His professional career didn't live up to expectations, and Porter began using drugs.
"I took a ride with the devil," Porter told the Star Tribune in a 2001 interview. "And the devil picked me up and rolled me for a while. But I always knew, deep down inside, I felt God wasn't through with me yet."
By 1985, he was out of money, addicted to cocaine and sleeping on the couch at his mother's house in Florida, the newspaper reported. After rehabilitation at Hazelden in 1989, he moved to a halfway house in St. Paul and began turning his life around.
In 2002, Porter's 1971 Villanova teammates gave him his trophy. Porter called it one of his most memorable moments.
Porter became a probation officer for Ramsey County in 1995, where he supervises adults who have been released from prison or sentenced to probation. He oversees violent and nonviolent offenders, making sure they follow the law, as well as terms of their release.
Chris Crutchfield, spokesman for Ramsey County Community Corrections, said he wouldn't talk much about the case because of the open police investigation. Porter was at work as scheduled Friday before he disappeared, Crutchfield said.
"He is extremely well-liked and is extremely popular here," Crutchfield said Tuesday. "We are all very concerned and our thoughts are with him and his family and friends. He really is a great guy."