Josh Richardson — the 40th overall pick in the 2015 NBA Draft — has agreed to terms on a three-year, $2.5 million contract with the Miami Heat, league sources told RealGM.

Richardson’s deal is fully guaranteed for the first season and partially guaranteed the second year, sources said.

Out of the University of Tennessee, Richardson went from uninvited to the Draft Combine and left off mock drafts to selected and a guaranteed NBA contract. The 6-foot-6 guard rose on draft boards of NBA organizations during the pre-draft process with strong workouts and disposition, flying for workouts from his home in Oklahoma City.

Richardson averaged 11.8 points, 2.8 rebounds, 1.7 steals and 1.6 assists in 10 summer league games in Las Vegas and Orlando — performing between both guard positions.

The Heat envision Richardson, 21, to have an immediate impact on the defensive end and transition into a backcourt role.

As a senior at Tennessee, Richardson had averages of 16 points, 4.5 rebounds and 3.6 assists per game.

The Miami Heat are waiving forward Henry Walker, league sources told RealGM.

If Walker clears waivers, a return to the Heat is still possible.

Through the NBA Development League, Walker earned a call up to the Heat last season, a miraculous perseverance to turn a fleeting career into a comeback story.

Walker averaged 7.3 points, 3.4 rebounds and 1.1 assists in 24 games for the Heat. The 6-foot-6 stretch shooter shot 34.1 percent from three-point range in over five attempts per game.

Walker, 27, has played five NBA seasons for Boston, New York and Miami.

The Boston Celtics have acquired Zoran Dragic and a second round pick from the Miami Heat.

The pick is unlikely to ever change hands.

Miami will also send cash to Boston to help cover Dragic's salary. The trade helps the Heat considerably with the luxury tax.

The trade did not upset Goran Dragic, who is hoping his brother will get more chances at playing time with the Celtics.

The Celtics were able to take Dragic into their salary-cap space.

The Orlando Magic will acquire Shabazz Napier from the Miami Heat, according to sources.

The Heat will acquire a future protected second-round pick.

Hassan Whiteside remains focused on the coming season and not his free agency in the 2016 offseason.

ESPN recently projected an average salary of $18.8 million per season for Whiteside next summer.

"I don't really get caught up in the numbers," he said of what next summer could deliver. "I'm just excited that I get to play with the Heat for another year. I'm not really thinking about the numbers right now, until free agency. I'm just really excited about this season."

Whiteside emerged this past season and is in his first stable offseason after bouncing around the basketball world.

Undrafted forward Greg Whittington is scanning three partially guaranteed deals out of the Miami Heat's summer league team, league sources told RealGM.

A standout at Georgetown, Whittington went undselected in June's NBA Draft, but has gained traction through summer league with the Heat in Orlando and Las Vegas.

Whittington, 6-foot-8, is averaging 15.7 points per game so far in the Vegas summer league.

Chris Bosh's health scare in which he missed the second half of the season with blood clots on his lung has triggered a renewed passion for the sport.

Bosh expects to be 100 percent ready by the start of training camp.

"That's renewed my passion," Bosh said at halftime of the Heat's 101-69 summer-league loss to the Boston Celtics at Cox Pavilion on the UNLV campus, where he watched as a spectator. "You don't miss anything until it's gone. It’s good for me to miss the game right now."

Bosh is still taking blood-thinning medication for at least a couple more weeks. 

"It's a little bit tougher getting back on that court if you haven't played in a while," said Bosh, who has been conditioning the past month. "I'm kind of working through that. It's good to get it out now as opposed to later. I feel good. Shot feels good. The conditioning is coming along."

Bosh is excited to finally have a chance to play with Goran Dragic.

"It will take some time," Bosh said. "We're going to have to figure out our roles and everything. It's just going to be a constant conversation.

"Pick and roll is going to be huge. I love a guard that attacks. That's always good for me. With chemistry, that's something that we’re going to have to get on the same page."

The Miami Heat have signed center/forward Amar’e Stoudemire, the team announced.

“We are very fortunate that a proven All-Star like Amar’e has chosen the Miami Heat,” Pat Riley said in a statement. “He is going to bring gravitas, leadership and a hardworking mentality to our team as we look to win another Championship in Miami.”

Stoudemire played for the New York Knicks and Dallas Mavericks last season.

The Miami Heat are approximately $13 million over the projected tax line and have made both Mario Chalmers and Chris Andersen available for nothing.

The Heat have also made Shabazz Napier available as they look to create extra cap room for next summer.

The Miami Heat have signed forward Justise Winslow.

Winslow cannot be traded for 30 days.

Winslow, who helped Duke to the 2015 NCAA Championship as a freshman, appeared in 39 games (all starts) for the Blue Devils and averaged 12.6 points, 6.5 rebounds, 2.1 assists, 1.33 steals and 29.1 minutes while shooting 48.6 percent from the field, 41.8 percent from three-point range and 64.1 percent from the foul line.