The NBA, NCAA and National Association of Basketball Coaches have joined forces to offer a proposed solution to prevent underclassmen from leaving early for the draft if they aren't assured of being a high pick.

The proposal, the result of a series of meetings first held at the 2014 Final Four, would move the withdrawal date for American college players to late May, nearly five weeks later than the current late-April date.

Key Points to the Plan • Would move the date college players can withdraw from the NBA draft back about five weeks -- from late April to late May. • Underclassmen would participate in an invitation-only combine in mid-May that would allow NBA teams to evaluate them and offer feedback on their draft prospects. Combine would include seniors, underclassmen and international players (currently, if an underclassman submits official paperwork to declare for draft, he forfeits his eligibility and cannot return to school). • Invitation-only combine would replace the traditional Chicago draft camp. • If a player submits draft paperwork and is not invited to the NBA combine, the recommendation is to withdraw from the draft and return to school. • Could be voted on by the NCAA in January and take effect in time for the 2016 draft. • It's the work of the NBA, the NCAA and the National Association of Basketball Coaches.

"This may be one of the best things the NABC has ever done," said Kentucky coach John Calipari, who has had players leave school who weren't lottery or first-round picks -- players who could have benefited from knowing where they would be drafted. "This is the first time the NABC understood that they represent the players."

The current deadline to declare for the draft would remain in late April, as stated in the collective bargaining agreement between the league and the players' association (this year's deadline is April 26). The official withdrawal date of 10 days before the draft (mainly for international players) would not change.

Under current NCAA rules, once an underclassman submits the official paperwork to the NBA to declare for the draft, the player forfeits his eligibility and cannot return to school.

If the proposal is accepted, underclassmen would be able to participate in an invitation-only combine in mid-May that would enable NBA teams to evaluate players and then offer feedback on their draft prospects. The pool would include all draft-eligible players: seniors, underclassmen and international players. But Dan Gavitt, NCAA vice president of the men's basketball championship, said the finite number wouldn't change if a player withdrew. The goal would be to increase the current NBA draft combine number by 20 to 30 percent (currently 65 to 70 players attend the draft camp in Chicago annually).

"Now, when you put your name in, if you're not invited that should tell you to go back to school," Calipari said. "Now after the combine you can make a decision -- go back to school or choose to go."

Kiki Vandeweghe, the NBA's vice president of basketball operations, said an invitation-only combine would be similar to the Chicago draft camp. But unlike the current model, it would include underclassmen who have remaining college eligibility.

"What we're looking at is not perfect," Georgetown coach John Thompson III said, "but it gives them a true sense of where they stand and where they can get feedback from NBA teams to where it's not Joe Blow at the barber shop. 'Am I invited or not invited?' Then, after that, once the combine happens, they can get feedback from the pro teams and hopefully that can happen. They would know exactly where they stand. It allows the student-athletes to make an educated decision."

UCLA athletic director Dan Guerrero, who chairs the new NCAA Division I council under the new governance structure, in which subcommittees will handle specific legislation for men's basketball, women's basketball and football, said the proposal could take effect in time for the 2016 draft. Gavitt said while there's no guarantee, there is a strong chance the proposal can be voted on in January if the legislation is proposed in September.

"It's a very, very sound concept and provides an opportunity for student-athletes to determine if they should stay in the draft," Guerrero said. "There is an alignment of vision with the NABC, [NCAA] men's basketball committee and the NBA. This is the kind of legislation that is good for the game."

"The message being sent to an underclassman not invited would be 'Your odds of getting drafted are slim and none.' That's a powerful thing, and it takes the coaches and the NCAA out of the mix. This is an NBA evaluation." Dan Gavitt, NCAA vice president of men's basketball championship

NBA commissioner Adam Silver supports an age limit for going pro of two years out of high school instead of one year out of high school and a player being age 19. National Basketball Players Association executive director Michele Roberts does not support the two-years rule. The CBA is not open to being renegotiated until 2017. Allowing underclassmen to participate in NBA-sponsored workouts -- something that was once permitted -- would be one avenue to stem the flood of marginal first-round picks from remaining in the draft. Prior to 2009, underclassmen were allowed to go to workouts and the draft camp. The draft rule continued to change with who could pay for the players to attend workouts. Policing whether agents paid for trips or if families reimbursed NBA teams for the workouts became a nightmare for the NCAA enforcement division and school compliance offices. Then, in 2011, legislation was adopted to one date in late April, forbidding underclassmen from testing the draft process.

"The way it is now, so many of them are not getting the information they need," Calipari said. "If we stay on this path, watch where the college game will go. It's the best decision for the kids."

Calipari, Thompson, Duke's Mike Krzyzewski and Michigan State's Tom Izzo were some of the high-profile coaches who were in on the proposal, with NABC director Jim Haney coordinating the effort. Gavitt credits Haney for putting all parties on the same page.

"The message being sent to an underclassman not invited would be 'Your odds of getting drafted are slim and none,'" Gavitt said. "That's a powerful thing, and it takes the coaches and the NCAA out of the mix. This is an NBA evaluation. Then, if you go, a few days after the process, there will be communication from all 30 teams with detailed projections of potential lottery pick on down. It's a significant first step, and hopefully the players' association will see that we are trying to improve the game at every level and the decision-making process for the kids and families."

Vandeweghe said the NBA wants underclassmen to make educated decisions. Under the current are-you-in-or-out, late-April deadline structure, "it's so quick to make a decision."

Vandeweghe said the hope is that this is the way in which the players can get the "straight scoop. I hope we can get some traction on this," he said. "It would be good for everybody. The kids would come out and compete against each other and see where they are."

The NBA altered the combine for this coming May, with players actually playing ball instead of solely doing drills. But the ongoing issue has been agents advising players who could be taken in the first round not to participate in the combine.

The NBA is hoping that underclassmen will wait to sign with an agent until they're advised of their draft stock. The league office is hopeful that agents will recognize the value of a true evaluation.

"In the long run, we want players who are better prepared" coming into the NBA, Vandeweghe said. "We want them to take advantage of hearing from the people drafting them. That's the idea, not get it secondhand."

The ACC coaches originally proposed the legislation in 2011 that changed the NCAA NBA draft deadline to late April. The reasoning behind it was so they wouldn't get burned by being unable to replace players on scholarship during the spring signing period. But now the coaches are going back on that premise.

"You're not going to find guys when [the underclassmen] come back later," Thompson said. "It might make things more difficult in terms of scholarships. But no system checks all the boxes and makes every entity feel good. But at the same time as it relates to our kids, they shouldn't rely on misinformation and partial information. We have to get them as much information as possible."