WALTHAM, Mass. -- The Celtics are currently operating without a true backup point guard behind Rajon Rondo, preferring instead to make use of what they currently have at their disposal. Though Jason Terry and Courtney Lee both spent time in the Celtics' first two preseason games handling the ball behind Rondo, the player that has perhaps tried to fill that role most exclusively is Jamar Smith, who the Celtics signed to a partially guaranteed deal following a successful stint at summer league.

Though Smith is billed more as a natural scorer with a long-range shooting touch, at 6-foot-3, he'll have difficulty distinguishing himself among the influx of more seasoned players Boston already has at the shooting guard position. Boston is using the preseason to see if Smith can be molded into a backup point guard, and even though he didn't play major minutes in either of the first two preseason games, his time on the floor revolved around facilitating the offense.

Doc Rivers said he's still looking for Smith to be more consistent, though he understands he's trying to lead a squad of veterans, while going head-to-head with Rondo in practice.

"[Smith hasn't] been consistent yet. Listen, I wouldn’t want to have to guard Rondo everyday in practice," said Rivers. "That would be no fun. I think Jamar would probably echo that. I don’t know if he’s a point or not -- and that’s one of the things we’re working and we’ll find out.

While he's had limited success in just 24 total minutes of preseason game action, Smith certainly looks to be making a concerted effort to try and get his teammates involved. Though he hasn't registered an assist, Smith thinks he's becoming more comfortable in finding the right balance of scorer and playmaker.

"I've been able to balance it. I don't think it's taken away from [scoring]," Smith said after practice on Thursday. "It's just, for me, learning -- because I'm a scorer -- learning when to look for my shot, when to get people involved. Understanding who's on the floor with me, and understanding who I have to get the ball to, because there are a lot of people on this team that demand the ball, because they're so good and they can score anywhere on the floor. I have to understand that."

An accelerated learning curve is almost a necessity for Smith at this point, as he's one of a handful of players on the bubble for the team's final roster spot. Finding his niche as a backup point guard might be his best chance to make the team, as, no matter how hard the injury bug might hit Boston this year, it's difficult to envision the team ever lacking depth at the two-guard spot, especially when Avery Bradley returns.

While Rondo might be a tough cover during practice, he's been one of Smith's best assets, leading both vocally and by example.

"You've just got to be observant," Smith said. "The best way I learn is just watching Rondo understand where Courtney likes the ball. He likes to get the ball out in transition, he's one of our better scorers in transition. And, [Terry], if his man is a step late, it's going down, so all you have to do is get him the ball where his man is a step late. You dribble at his man, get him off of down screens and stuff like that.

"[Rondo's] teaching me a lot, as far as when to push, when to look for my shot, when to get my teammates involved, when I need to slow it down and get us in a set. He's teaching me a lot of stuff like that."

Count on Smith trying to soak up every piece of knowledge Rondo dispenses, as his future as a Celtic could easily come down to how well he can apply those lessons on the court.