ORLANDO -- Boston Celtics coach Brad Stevens said he tried to put James Young into Friday's lopsided win over the Washington Wizards but was told the second-year swingman couldn't play due to a sore shoulder after sleeping on it wrong.

“He told me his shoulder hurt; couldn’t play," said Stevens. "He went through some rehab that day, went through some rehab [Saturday] morning, practiced, though we didn’t go full speed [Saturday], and is available [Sunday versus the Magic] pending his warmup. I tried to put him in [on Friday] with six minutes to go."

Young, the No. 17 pick in the 2014 draft, has played only four minutes in two appearances this season and made the only shot he took -- a 3-pointer during three minutes of trash time in a loss to the Atlanta Hawks last week.

The Celtics have assigned Young to the Maine Red Claws of the NBA D-League six times since the start of November for practice and game reps when he would otherwise be inactive. Young has averaged 20 points on 38 percent shooting in four appearances for the Red Claws this season.

With the Celtics shorthanded in the backcourt while starting guard Marcus Smart recovers from a left knee injury, Stevens has stressed that Boston needs more contributions from its young perimeter players. The fact that Young wasn't available -- particularly in a game he was dressed for -- will leave some scratching their heads.

Young said his shoulder remains a bit sore, but deemed himself available for Sunday's game.

Asked if he's ready to step up if needed, Young said, "I’ve been ready for a while. "I'll probably have a chance to play [Sunday versus the Magic] so we'll see what happens."

The question is will Stevens have the confidence to go to him after he wasn't ready on Friday? Stevens desires more perimeter depth to allow the Celtics to shuffle swings like Jae Crowder and Jonas Jerebko to the power forward spot in smaller lineups, something that has worked well for Boston recently.

"The bottom line is we need guys [like rookies Terry Rozier and R.J. Hunter], we need James Young to be ready," said Stevens. "We need those guys to continue to give us good minutes so that we feel like we can play small with Jae or Jonas in at the 4."

Added Stevens: "I think our biggest challenge right now is our depth on the perimeter is not where our depth at the traditional 4-5 is. So when you go small, you have five guys sitting there that are good players. That’s a challenge. It’s one of the things that we’ve got to continue to figure out our best way because we don’t have a lot of options with regard to playing wings at the 4 on our team beyond Jae and Jonas. So that’s why [the younger players] are so critical and it’s why it’s really important that our young perimeter players continue to develop because we need to build that depth on the perimeter."