It seems like two prominent big men who play reduced roles with their respective teams this season are having uncertain futures, with the Chicago Bulls' Joakim Noah and the Boston Celtics' David Lee being on the trade rumor mill as of late.

For Noah, who is currently sidelined with a shoulder injury, this 2015–16 National Basketball Association (NBA) regular season is all new for him.

Since joining the Bulls in 2007 as the ninth overall pick, Noah was the starting center and through the years provided hustle and energy.

The 30-year-old center was even one of the faces of the Bulls as they continued their transformation to a contending team. 

But this season, Noah lost the starting role and with his minutes lessened, his production which started to go downhill since last season decreased further. 

Noah is averaging 4.5 points (career-low), 8.8 rebounds, 3.8 assists, and 1.1 blocks in 22.3 minutes played per contest. 

The role he used to dominate now belongs to another veteran in Pau Gasol and second-year big man Nikola Mirotić. 

According to Bleacher Report, Noah is also not fitting in new Bulls head coach Fred Hoiberg's system which makes him the "easiest player to move."

Gasol said previously that Noah's energy makes him an important player for Chicago, but reserve forward Taj Gibson is meshing better with Hoiberg's system which will likely make him stay longer in the team than the nine-year veteran. 

Meanwhile with the Celtics, Lee is having a repeat of last season when he was rarely used coming off the bench for the defending champions Golden State Warriors. 

After winning the championship, the Warriors traded the 32-year-old player to Boston, with Lee believing that he will have a bigger role in the new team, like the one he had with the New York Knicks and his earlier seasons with Golden State. 

But now with the Celtics, Lee is again finding it hard to land a significant role as he averages 7.4 points, 4.4 rebounds, and 1.9 assists in a career-low 15.9 minutes per game. 

As the Celtics continue to thrive with younger big men like Jared Sullinger and Kelly Olynyk emerging, Lee is starting to lose his place in the rotation. 

In an earlier report, the winningest franchise in the NBA is reportedly making Lee available for trade deals.