Matt Chin: The second unit was a combined -20 tonight and dearly missed Marcus Morris' scoring presence. Boston struggled to find quality offense in the first half, which allowed Dallas to build a sizable lead going into halftime. The Mavs were also able to tie the game against Boston's second unit midway through the fourth quarter.
The C's ranked a palatable 14th in bench scoring before tonight, but their lack of playmaking and shot creation becomes apparent when Terry Rozier and Marcus Smart aren't able to effectively quarterback. Kyrie Irving and Co. can't be asked to bail out the reserves on a regular basis.
Staggering Irving and Al Horford's minutes has worked when deployed, but reverting back to that tactic would be disappointing given their advanced two-man chemistry right now. Simply put, Brad Stevens needs to find the right balance when both are resting. Shane Larkin and Daniel Theis played admirably, but bench consistency remains an overall question mark.
After allowing Dallas 57 points in the first half on 47.6 percent shooting and 6-of-13 from three, Boston locked the Mavs down in the second half. After the break, Dallas scored just 33 points on 14-of-44 shooting overall and just 3-of-15 from behind the arc. And one of those came right at the buzzer when the game was already decided.
The Celtics have only been able to rely on Kyrie Irving and Al Horford for consistent offense from night to night. Jayson Tatum has been terrific, but goes quiet for periods during each game. Jaylen Brown has been a bit inconsistent with his scoring. Marcus Morris has been in and out of the lineup. And Terry Rozier and Marcus Smart very much remain works in progress on offense.
All of that said, the offense has been improving. As it has, the defense has slipped a bit. A night like tonight, when the offense wasn't there for long stretches, it was nice to see the Celtics can still get back to their trademark defense when necessary. Coaches have an old saying that goes "You can have off nights on offense, but you should never have an off night on defense." If Boston keeps defending the way they have most of this year, they won't have many off nights in terms of the Win/Loss column either.