Brian Babineau/NBAE/Getty Images

Brandon Bass' minutes -- and production -- are down this season.BOSTON -- Amid diminished playing time and underwhelming production, Celtics forward Brandon Bass expressed frustration over his role with the team after Thursday's loss to the New York Knicks.

Bass finished with four points and two rebounds over 19 minutes, 41 seconds of playing time against the Knicks, then went scoreless with two rebounds in 18:49 during Friday's double-overtime loss to the Hawks in Atlanta.

A quiet but steady source of consistency for the Celtics last season, Bass played in 59 of 66 games and averaged 12.5 points and 6.2 rebounds over 31.7 minutes, which paved the way for a new three-year, $19.3 million contract last summer. But through 43 games this season, Bass hasn't had nearly the same impact he did last year. His numbers have dipped to just 7.4 points, 4.9 rebounds and, perhaps most importantly, 26 minutes per game.

"I mean, at the end of the day, you want to do better than you did last year or the same," Bass said after Thursday's loss. "So, it's a little bit frustrating. But, it's a team game. You've just got to keep working and hope everything works itself out."

When asked about his production, Bass suggested fewer minutes have played the biggest role.

"I mean, if you consider my numbers down, you've got to look all around," Bass said. "So if you see my numbers down then you see my minutes. If my minutes are down, OK, that plays a role. Then you look at how many opportunities I get -- that plays a role. And you get what you get."

Asked if he's satisfied with the season he's having, Bass was very direct: "No, I'm not satisfied."

Bass' basic stats aren't the only ones that pale in comparison to last season. Per Basketball-Reference, Bass' usage rate of 15.6 this season is down considerably from 19.8 last season (and 19.2 for his career), which suggests he's not being utilized as much on the offensive end. His shooting numbers fall in line with that, as he's taking nearly four fewer shots per game this season, and he's even seen a decline in field goal attempts from some of his most common shooting areas on the floor. Per HoopData, Bass' attempts from 10-15 feet are down from 2.1 last season to 1.5 this season, and from 16-23 feet his attempts are down from 5.1 to 3.2.

Bass dismissed the idea of being more hesitant on the offensive end this season, suggesting some different offensive schemes haven't granted him the same looks as last year.

His rebounding figures haven't dipped dramatically, with his defensive rebound rate down only a few percentage points and his total rebound rate nearly identical to what it was last season. Bass' offensive rebound rate has actually increased from 6.3 to 7.8.

His starting job seems secure for now, but that hasn't been true all season. Just last month the Celtics experimented with starting Jason Collins alongside Kevin Garnett, which relegated Bass back to the bench. But as that experiment flamed out, Bass was thrust back into the first five and he's started 33 of 43 games overall.

"Absolutely frustrating," Bass said of his shifting role. "But when you're a role player, that happens. So you've just got to make the best of your time on the court."

Asked what he would like to see different over the second half of the season, Bass offered: "Everything that comes with having better production. That's what I would like to see improve. I would like to see me being more efficient with the shots I do get, making them, try to be perfect out there. Minutes go up."

When considering Bass' diminished production, it's not so much about what's changed for him as much as it is what's changed for Boston. Last season, especially once Chris Wilcox was forced out due to a heart ailment, Bass was Boston's only real option at power forward. Who else was Doc Rivers going to turn to for extended stretches? Ryan Hollins? JaJuan Johnson?

But this season, the emergence of rookie Jared Sullinger and the return of Jeff Green have certainly played a factor in Bass' minute totals. While Bass still fits well with Boston's starting five, Sullinger is deserving of more floor time and Green has spent stretches at the power forward position when the Celtics have sought a more versatile lineup.

Bass, though, has been in a state of flux as a result. He's had difficulty being as effective as he was last season in his shorter minutes and he doesn't necessarily have a clear-cut role on the team right now. While some players have more defined responsibilities -- Jason Terry is in Boston to score points, for example (not that he's done that particularly well so far) -- Bass doesn't have that one thing he does well every single night.

Last season he might not have excelled in one particular area, but Bass was steady across the board with his scoring, rebounding and defense. He was solid, plain and simple, and the Celtics were solid with him on the floor. Last season, Boston was plus-4.3 per 100 possessions with Bass on the court. This season? The C's are a minus-7.3 per 100 possessions with Bass on the floor.

But unless Sullinger hits an unwelcome rookie wall or Green goes down with an injury, it's difficult to see Bass' minutes suddenly increasing.

Which means he might just have to try to do more with less for Boston right now. It's not a glamorous solution, and he might not have the same kind of looks and overall contributions that he did last season -- and perhaps expectations should be lowered a bit as a result -- but unless he suddenly starts rebounding at Sullinger's rate or the Celtics retool their offense to get him more looks, this might be Bass' reality for the foreseeable future.