Lee, a 6-foot-5, 200-pound junior, was UCLA's second-leading scorer last season with 13.1 points a game, and has until May 8 to decide if he wants to return to school and continue playing for the Bruins.
He is the second UCLA player in two days to declare for the draft. Forward Tyler Honeycutt also did so Monday but plans on hiring an agent, so he will relinquish his college eligibility.
ESPN NBA Insider Chad Ford projects that Lee will go in the second round, if he is drafted at all. Lee will work out for NBA teams from April 28 through May 8 and get feedback about his draft position.
"I feel like I'm a first-round draft pick, but my opinion really don't mean nothing," Lee said. "If I'm not a first-round draft pick as of right now. I can improve my stock in the workouts."
How quickly he recovers from recent knee surgery may be a major factor in those workouts. Lee had cartilage removed from his left knee last week, and said he hopes to be at 100 percent by the time the workouts begin.
"But you really don't know until you get out there and start doing the cuts and going against competition," Lee said. "You really don't know until you go out and start testing it."
Lee said the threat of an NBA lockout would not alter his decision.
UCLA coach Ben Howland said entering the draft without hiring an agent is a win-win proposition for Lee because he retains the option of returning to school if he doesn't like what he hears from NBA teams.
"Malcolm is smart," Howland said. "He knows that from that feedback, if someone doesn't tell him we're going to take you in the first round, then it doesn't make sense."
UCLA has been projected to be as high as a top-10 team next season, but with the departure of Honeycutt and now possibly Lee, the Bruins' stock is dropping.
Howland said that Lee, who is the team's best defensive player, would be "a huge focal point for our team next year both offensively and defensively" should he withdraw from the draft. Lee acknowledged that would factor into his decision.
"The potential of what the team could be next year, that could be a deciding factor," he said. "If I were not to come back we can still be a top team because we do still have talent."
Peter Yoon covers UCLA for ESPNLosAngeles.com.