Patterson's decision has the potential to catapult Kentucky and new coach John Calipari into the 2010 national title race.
Patterson, a 6-foot-9 forward, is arguably the top returning forward in the SEC after averaging 17.9 points and 9.3 rebounds for Billy Gillispie this past season. Patterson was projected as a first-round pick in the June 25 draft. The NBA's deadline to withdraw from the draft is June 15.
Patterson was second on the team in scoring behind junior guard Jodie Meeks, who also declared for the draft. Meeks is considered be a borderline first-round pick. The Wildcats are also in the running -- with Duke, Miami and Florida -- for the top point guard in the country, Word of God Christian Academy's John Wall of Raleigh, N.C.
"I want to help Kentucky compete for a national title, and even more than that win its eighth national championship," Patterson said in a statement released by the school. "I'm also really excited about playing for coach Cal and developing my game in the dribble drive offense."
The Wildcats needed an experienced player to return in Calipari's first season.
"Oh my gosh! Now I get a chance to coach this kid for a year," Calipari said in reaction to Patterson's decision. "He's going to graduate in three years."
Calipari said Patterson went through workouts with the Wildcats and enjoyed the new offense.
"He said, 'Wait a minute, I want to do this,'" Calipari said. "He said he would be wasting everybody's time by staying in the draft, mine, yours and the NBA and 'I just don't want to do it.'"
Patterson probably would have been one of 65 players invited to the NBA's draft combine in Chicago May 27-29.
Calipari said he'll use Patterson the way he handled Robert Dozier at Memphis. That means Patterson won't only be posting up but also facing the basket as an offensive, driving option. Calipari said he will look at playing Patterson with highly-touted newcomers 6-10 Daniel Orton and 6-9 DeMarcus Cousins.
Kentucky has signed point guard Eric Bledsoe and Miami Dade Junior College small forward Darnell Dodson. The rotation of Patterson, Cousins, Orton, Dodson, Bledsoe and returning perimeter players DeAndre Liggins and Darius Miller gives the Wildcats an impressive nine players. Adding Meeks would give them 10 formidable players and Wall would make Kentucky's 11 in the conversation with Kansas, Michigan State and possibly North Carolina and Villanova as some of the favorites for the title.
Patterson's return means Kentucky has 15 players on scholarship for next season. The NCAA allows a maximum of 13, meaning two players will lose scholarships either by departure or giving them up to stay on the roster. The number goes up to three scholarships needing to be vacated with Meeks, four with Wall. But Calipari said that the scholarship situation will work itself out in the coming months.
Kentucky failed to reach the NCAA tournament this past season and lost at Notre Dame in the NIT quarterfinals. Kentucky reached the NCAA tournament in Patterson's freshman season but he was injured and didn't play the final few weeks of the season.
Andy Katz is a senior writer at ESPN.com.