PORTLAND — The underdog remained when the Maine Red Claws made their first round of cuts Sunday, reducing their roster to 13.

Former University of Maine point guard Raheem Singleton appears to have made the team after four players were released Sunday.

After Sunday’s cuts, the Red Claws’ total roster is down to 13, which includes two NBA players sent from the Celtics. One more player must be released by Wednesday. NBA D-League rosters are limited to 10 players, along with as many as three NBA players.

After the cuts, Singleton is the only back-up point guard on the team. First-round pick Shelvin Mack is the starter. And Singleton is the only rookie remaining, not counting NBA players Kris Joseph and Fab Melo. Every NBA D-League roster must have at least one rookie.

The four players who were cut included 6-9 forward Ron Allen and three rookie guards — DeQuan Brooks, Cervante Burrell and Farnold Degand.

“What separated Raheem from the rest of the (other three guards) was his work ethic and his attitude,” Red Claws coach Mike Taylor said. “We felt he was the best defender of the four players and the most natural point guard of the four.”

Singleton, 23, came into preseason camp last week having been invited after impressing the Celtics and Red Claws staff in a tryout in September. Taylor said Singleton was “probably the longest shot to make the team.”

Singleton, 6-foot, is not a flashy player or prolific scorer. But he can run the offense as well as play solid defense.

“My thing was not to get out-worked,” Singleton said. “At this level everyone is talented. Everyone can do certain things. I made sure every day that I controlled the things I can control — the effort, how hard I was going to work and playing tough.”

A sign of Singleton’s rise on the depth chart was his start in Saturday’s intra-squad scrimmage guarding Mack.

“Raheem held his own,” Taylor said. “His defense was a primary part that played in the decision. The great thing we like about him is that he wants it. He really wants it. That motivation is a great thing.”

The only way the Red Claws could cut Singleton now is if they gambled with only one true point guard. They would also have to designate Joseph or Melo as their required rookie on the team.

But if both Melo and Joseph get called back up to the Celtics, Maine would be scrambling to sign another rookie.

Maine currently has a surplus of shooting guards with veterans Xavier Silas (6-5) and Champ Oguchi (6-6), Micah Down, a 6-8 guard/forward who was in the Celtics preseason camp, and 6-2 Corey Allmond a two-year pro drafted by Maine in the eighth-round of the D-League draft.

“They’re are a lot of good players ahead of (Allmond),” Taylor said. But “Corey Allmond has played so well. He has a great ability to score and shoot the ball. We value that.

“We want to give ourselves some options as we build the team.”

Allmond scored 18 points in Saturday’s scrimmage.

At the forward spot, the Red Claws have the 6-7 Joseph, 6-8 Chris Wright, 6-6 Omar Reed (a fourth-round draft pick), and Down.

Chris Ayer, a 6-11 D-League veteran whom the Red Claws traded for, can play the power forward or center position. The other centers are 7-footers Melo, Brian Cusworth (a prospect sent here by the Celtics) and Scott VanderMeer, a seventh-round draft pick.

Of the players released, two came via the draft — Burrell (fourth round) and Allen (sixth) — while Brooks and Degand were invited from the same tryout Singleton attended.

The Red Claws season begins Friday in Canton, Ohio. The home opener is Nov. 30.