ORLANDO, Florida (AP) ― The Houston Rockets and Boston Celtics tipped off Orlando Summer League play concerned about how major additions will fit into their success next year.

Prized free-agent Dwight Howard is heading to Houston and the Celtics hired former Butler coach Brad Stevens to replace Doc Rivers.

Rockets coach Kevin McHale said Sunday morning that the 27-year-old Howard should be a “seamless fit” with Houston.

“He can run the floor, block shots, he can finish and that’s all the stuff we want in our system,” McHale said after watching his summer league team defeat the Philadelphia 76ers 88-80. “We’re looking forward to developing something special.”

The 6-foot-11 Howard played his first eight NBA seasons with Orlando and last season with the Los Angeles Lakers.

Meanwhile, Stevens has noticed one immediate difference between the college game and the NBA.

“Summers are different,” he said. “I’m here watching these games, hiring a staff, watching a lot of film. There’s a lot to do.”

It’s been a whirlwind few days for Stevens since he was hired by the Celtics on July 4.

Boston president Danny Ainge, also at the Celtics-Orlando Magic game on Sunday morning, said the expectations for Stevens are realistic.

“First of all, all coaching openings except for Jason Kidd, are for teams not having success,” Ainge said.

“Organizations are impatient, fans are impatient, sports talk media is impatient. We live in a world of here and now and expectations are so high. We have fair and realistic expectations and we will manage them.

“Brad is humble, hard-working and about the process,” Ainge said.

“We’re not sitting over his shoulder. We know he’s going to make some mistakes. ... He’ll get better and better, learn the NBA game and be able to lead.”

The first inkling Ainge had about Stevens came when he and Celtics owner Steven Pagliuca were watching the 2010 NCAA championship game between Duke and Butler.