Analysis: Jayson Tatum likely to start opening night with Marcus Morris (knee) sidelined

The Celtics are stocked with plenty of young talent and Brad Stevens is wasting no time with putting those players to use opening night against the defending Eastern Conference champions.

The head coach announced after Sunday's practice that projected starter Marcus Morris would miss the first 7-10 days of the regular season due to soreness in his right knee. Stevens didn't officially announce a starting five without Morris available, but he hinted that the team would go with a group similar to what they've been using this preseason. Here's what the likely starting five will look like in Cleveland:

PG: Kyrie Irving
SG: Jaylen Brown
SF: Gordon Hayward
PF: Jayson Tatum
C: Al Horford

"I don't want to say because then I feel like I would be stuck to it," Stevens said when asked about his starting five on opening night. "But probably pretty similar to what we've been doing."

Jayson Tatum has started the last three preseason games for Boston at the power forward spot, which would indicate he's the likely choice for Stevens in that spot on opening night. Aron Baynes would be the other natural candidate for a frontcourt spot next to Al Horford, but that's unlikely to be the case with the Cavs starting Jae Crowder at power forward and Kevin Love at center on Tuesday night.

The Morris injury doesn't appear to be cause for alarm, at least for now. The 6-foot-8 forward was a late arrival to training camp after his assault trial in Arizona, so the team wants to take it slow with him to ensure his body and conditioning are where they need to be.

"Marcus, we've actually decided that he has had some knee soreness in the last couple days," Stevens explained. "With him getting here a little bit late, we feel like he needs a little more of a preseason. He will most likely be out here for the coming week-plus and then we will re-evaluate after that. They've done all the testing and structurally the knee is in good shape, but I think it is a quick turnaround to get here last week and play in a regular season game. It's going to be a little bit of time probably before he hits the court again. He did some of practice today."

The team expects to re-evaluate Morris sometime next week.

"It's something he came into camp with it bothering him a little bit," Stevens added. "He was able to go through everything. He's actually structurally improved, he's gotten stronger, feels better, but we just felt like after watching him practice yesterday and then talking to him, we felt like he's not quite full go. Better to be on the safe side. It's a long year. He's a really important part of our team. If he's at 80 or 85 percent now, let's get him to 100 instead of risking that getting lower or [it being] something you're dealing with all season."

BSJ Analysis: Starting lineup by committee was always going to be an option for Stevens this season, but it should be on display even more in the coming weeks with Morris sidelined.

Luckily for Boston, Baynes (knee) should be ready to go on opening night but the team will be better served to save him for the bench unit so he can battle Tristan Thompson on the boards. Tatum will get a tough first NBA assignment splitting his time defending LeBron James and Crowder at the forward spots, but he'll also get a chance to shine offensively with the starting unit. Cleveland's defense will be preoccupied with creators like Irving and Hayward all night, which should open the door for Tatum to get some open looks all around the court when the help defense leaves him.

Don't expect this starting nod to turn into a full-time gig for Tatum however when Morris is out. The Celtics face a couple of big teams in the first week of the season, including Joel Embiid and the Philadelphia 76ers on Friday night. Baynes could be called upon in those matchups to start in place of Tatum in order to take some of the physical onus off of Horford. However, a couple strong performances by the 19-year-old rookie out of Duke could convince Stevens to roll with the hot hand after the first couple of games.

Either way, it's a positive sign for the No. 3 overall pick that he has earned the faith of his head coach for such an important assignment early in the season. We'll find out pretty quickly whether he's up to the challenge.