With the regular season starting on Tuesday, Monday marked the deadline for teams to cut their rosters to 15 players. For the Phoenix Suns and Boston Celtics, this was a difficult decision, and they ended up waiving former first-round picks: Archie Goodwin and R.J. Hunter. Sadly, it also happened to be Hunter's 23rd birthday.

For those who saw Goodwin or Hunter in the right summer league or preseason game, this might seem crazy. Both have the potential to be rotation players, so what happened?

Let's start with Goodwin. Drafted No. 29 overall in 2013, the combo guard entered the NBA as the second-youngest player in the league. In his rookie season, Phoenix had Goran Dragic, Eric Bledsoe and Ish Smith in front of him in the backcourt. He was stuck on the bench for the short-lived Dragic-Bledsoe-Isaiah Thomas experiment, and his biggest opportunity came last year when Bledsoe and Brandon Knight were injured.

In fairness to Goodwin, he scored 20-plus points eight times in 2015-16 when he had an opportunity to play. The problem, though, is that he didn't do much more than score. During the course of his three seasons with the Suns, they tried to use him at point guard, but he never became much of a distributor. When he went to the D-League, he put up big scoring numbers, but rarely got assists. His lack of progress on the defensive end was worrying, too. The physical tools are all there, but he has some developing to do if he's going to stick in the league as more than a low-efficiency gunner.

Archie Goodwin dunks
Archie Goodwin can get to the basket. USATSI

The case of Hunter, the No. 28 pick in the 2015 draft, is more confusing. Instead of giving him three years to refine his game, the Celtics let him go after only one. This is partially a result of Boston general manager Danny Ainge's proficiency in acquiring draft picks during the past few years. He has done a great job of getting them, but if you can't package young players and picks for a superstar, then you'll have to get rid of some of them. The Celtics have stashed some players overseas, but could not find a better resolution than this for Hunter, who was competing with guard James Young for the last roster spot. This is not Hunter's fault.

Unlike Goodwin, Hunter has shown some versatility as a pro. He's a good passer and a high-IQ player, and he clearly put on some strength this past summer to better deal with the physicality of the NBA. Unfortunately, his best skill -- shooting -- has not translated to the league as planned. Despite being known for his beautiful 3-point stroke in college, Hunter made only 30.2 percent of his 3-pointers last season and 29.2 percent this preseason. That made him expendable to the Celtics because they've been impressed with what Young has shown since training camp started. It's also worth noting that Hunter is two years older than Young.

R.J. Hunter shoots a 3-pointer
R.J. Hunter is still a sharpshooter, in theory. USATSI

It's no fun to get cut on the eve of the regular season, but it's possible that this is good for Goodwin and Hunter. The way the Suns and Celtics were constructed, it was always going to be difficult for either of them to get significant playing time this season. Couldn't the Chicago Bulls use Hunter to space the floor? Couldn't the New York Knicks use Goodwin for backcourt depth?

In the next 48 hours, both of them could be claimed on waivers and wind up in better situations. Wherever they land up, though, they're going to need to keep working on their weaknesses. NBA teams aren't known for their patience.