Darko Milicic needs to stop dwelling, according to his coach. (Getty Images)

The Boston Celtics are accustomed to winning more than their fair share of mental battles during the Doc Rivers era.

Other than the occasional loss of composure from Rajon Rondo, the Celtics have been as rock-solid mentally as any team in the league. Intense and intimidating forward Kevin Garnett sets the tone, uber-professional Paul Pierce does his part and, until this summer, the laser-focused Ray Allen was on board as a model of reliability. The Celtics have thrived through countless injuries and come out on top of numerous back-and-forth playoff scraps largely because of their collective trust in each other and their unshakeability.

Enter Darko Milicic, a center who was amnestied by the Minnesota Timberwolves in part because his veteran coach, Rick Adelman, wanted him gone and because of a lack of focus and intensity. That guy hooks up with these Celtics? It's a strange/player team marriage, to be sure.

The Boston Globe reports Rivers' first impressions of Milicic's mentality, and it isn't all positive, as he calls out the Serbian for dwelling on his past rather than living in the present. 

"He just needs a chance; he just needs a team that wants him to do his job without asking him to be the No. 2 pick in the draft. We’re just asking him to be part of a group and part of a team. We give him roles on the team. I think he likes the roles that we’ve given him and he didn’t feel any extra pressure. So far so good. We just have to keep him in that frame of mind that he’s in now.

"You can see that he gets frustrated easy. So we’re trying to eliminate those episodes. Our thing right now with Darko is to play forward. From being around for a short time, as a coach I can probably feel he’s played his career backwards. He lives in the past a lot and we’re trying to get him to live in the future. I told him (Friday), the only time I’ll take you out is if you make a mistake and make another mistake because you’re thinking about the last mistake. I won’t take you out for making a mistake. So hopefully that works."

The extra attention Rivers talks about paying to Milicic isn't something you usually hear an NBA coach say about a 27-year-old. But Milicic, the famous No. 2 pick in the 2003 Draft whose name has become synonymous with "bust," isn't any ordinary 27-year-old. His NBA career has really been stuck in stasis; some years have been better than others numbers-wise but he's yet to make a meaningful mark in the league and he also hasn't seemed to develop a love for the game.

The easy conclusion was to write off Milicic. He's on to his sixth team in 10 years so it wouldn't be the first time. The Celtics didn't build their mental toughness by taking the easy way, though, and at a low-ball price he represented a no-risk proposition. If things click mentally, he's a nice addition to a frontcourt that can use some builk. If not, no real harm done, as long as Rivers has some Tylenol handy for the inevitable headaches.