Steve Kerr says Boston Celtics star Jayson Tatum will have an important role to play in the USA's pursuit of a fifth straight Olympic gold despite not playing in Sunday's opening win over Serbia.

Five-time All-Star Tatum, a key pillar of Boston's NBA championship-winning campaign last season, was a frustrated spectator on the bench as the USA romped to a 110-84 victory.

Kerr said Tatum was left out to accommodate the return from injury of Kevin Durant -- a decision he admitted looked "crazy" at first glance.

"It's really hard in a 40-minute game to play more than 10 guys," Kerr said. "And with Kevin coming back, I just went to the combinations I felt would make the most sense.

"It seems crazy. I thought I was crazy when I looked at it and determined these are the line-ups I want to get to."

Kerr however said Tatum would be ready to "make a mark" later in the tournament, describing the Celtics ace as the "ultimate pro."

"Jayson is First Team All-NBA three years in a row. He's one of the best players in the world," Kerr said. "And he's incredibly professional... so he'll make his mark."

Kerr added that the USA's star-studded squad had been urged to unite behind the cause of retaining their Olympic crown.

"The key to this whole thing is to put all the NBA stuff in the rearview mirror and just win six games," Kerr said. 

"Jayson is the ultimate pro, a champion, and he handled it well and he's going to be ready for the next one."

The Americans face South Sudan in their second group game on Wednesday before wrapping up the first round in Lille against Puerto Rico next Saturday.