The Brooklyn Nets had remained competitive in every game this season entering Friday's in-season tournament matchup with the Boston Celtics. However, with Ben Simmons and Cam Thomas sidelined in Boston, that streak ended with a 121-107 loss before a sellout crowd at TD Garden.

Here are three takeaways from Brooklyn's decisive loss.

Lonnie Walker continues Brooklyn breakout

Nets' Lonnie Walker IV with lightsaber

It's not a stretch to say Walker IV is in the running for Brooklyn's best player early this season. The minimum signing entered Friday's game leading the NBA in scoring among players averaging fewer than 25.0 minutes per game, posting 16.3 points per night in 22.6 minutes.

Walker was once again Brooklyn's best player while coming off the bench against Boston. He scored a team-high 20 points on 8-of-12 shooting, becoming the first player in Nets franchise history to reach double-figures off the bench in his first eight appearances of a season. The stretch matches Walker's longest double-digit scoring streak of his career.

With Thomas sidelined for two weeks and Simmons battling a hip injury, Walker's ball handling and three-level scoring will only grow in importance as Brooklyn looks to stay in the winning column.

Nets feel absence of two primary ball handlers

Simmons and Thomas are among the main reasons the Nets had the NBA's 10th-ranked offense entering the Boston matchup. The former had led a transition attack averaging 19.8 fastbreak points per game, the second-most in the NBA, while Thomas' elite shot creation carried the halfcourt offense at 27 points per game on 48 percent shooting.

With the pair out on Friday, Mikal Bridges, Spencer Dinwiddie and Cam Johnson had trouble getting anything going against the Celtics' third-ranked defense. The trio shot a combined 11-of-31 from the field (35.5%) with five assists and five turnovers.

While he has remained efficient from the field, Bridges has struggled to find his three-point stroke early this year. He shot 1-of-5 from deep Friday and is shooting 30.8 percent for the season. Dinwiddie has been hit-or-miss this season while playing a heavier off-ball role amid Thomas' breakout, and Johnson had missed Brooklyn's last seven games with a calf strain before returning against Boston.

The Nets struggled to generate transition opportunities while being punished on the defensive glass. Without Simmons and Thomas' ball-handling, Brooklyn's new lead trio struggled in the halfcourt against a formidable Boston perimeter defense featuring Jrue Holiday, Derrick White, Jayson Tatum and Jaylen Brown.

Brooklyn's small-ball lineup gets punished on glass

Nets' Nic Claxton holding a first aid kit amid injury

The Nets have embraced a small-ball-heavy rotation with Nic Claxton sidelined. It had yet to significantly hurt them in the rebounding game entering Friday, with Brooklyn posting the league's fourth-best defensive rebounding percentage for the season.

However, Simmons' 10.8 rebounds per game (10th in NBA) were a major reason for that success. With Simmons sidelined Friday, Boston won the offensive rebound battle 17-9 on its way to a 29-5 advantage in second-chance points. The Celtics shot 10-of-17 (58.8 percent) on second-chance opportunities in the win.

Day'Ron Sharpe played just eight minutes in the loss after an impressive fourth-quarter showing during Wednesday's win over the Los Angeles Clippers. Head coach Jacque Vaughn called Ben Simmons “day-to-day” pregame. If the 6-foot-10 point forward remains sidelined, Vaughn will need to decide between sacrificing size with continued small-ball lineups or shooting and offensive creation with Sharpe on the floor.

Either way, the Nets will need a far more engaged rebounding effort if they hope to stay competitive amid a series of injuries.