Joe Mazzulla rotation changes and Celtics roster shifts

Joe Mazzulla subbed Jayson Tatum out midway through the first quarter to help the starters find consistency. This rotation change led to a 33 point scoring advantage for the starters in their last two games against Orlando and Golden State. Tatum discussed these pattern changes with Mazzulla to prioritize team needs. Payton Pritchard remains a central part of the rotation after signing a two-year, $44.2 million extension. Pritchard averaged 17 points, 5.2 assists, and 3.9 rebounds last season. He also averaged 32.4 minutes per game and shot 39.4% from beyond the arc. Pritchard hit at least five 3-pointers in 16 games last season and recorded a triple-double with 30 points, 14 rebounds, and 11 assists. His 37.7% 3-point percentage ranked 11th-highest among players with his volume of attempts. He also scored 43 points and hit 10 3-pointers in a game against March 5, 2025. The team used the offseason to reduce payroll because the NBA luxury tax and the second apron forced roster moves. This included losing Kristaps Porzingis, Luke Kornet, and Jrue Holiday. Holiday, who recorded 28 points, 7 rebounds, 8 assists, and 4 steals in a single conference finals win, previously played for four different teams. Mazzulla holds a .740 win percentage after recording 182 wins and 64 losses.

Veteran management

The Celtics face a talent gap because Jayson Tatum remains out for the 2025-26 season with a torn Achilles tendon. Jayson Tatum’s $54 million salary accounts for 35% of the salary cap. You know how much roster stability matters for a team attempting a repeat. The team loses 51 years of experience and four championship rings with the impending departure of Al Horford. Horford, now with the Golden State Warriors, follows a strict load management plan. Steve Kerr confirmed Horford will not play both ends of back-to-back games this season. The Warriors have 15 back-to-back games scheduled this season. Horford enters his 18th NBA season after averaging 9.0 points and 6.2 rebounds in 60 games last year. He averaged 27.6 minutes per game in a versatile role. His ability to space the floor creates perfect spacing for Stephen Curry and the Warriors’ motion offense. Holiday, who signed a $134.4 million extension, provides veteran leadership. He turned 34 on June 12. His departure forces the team to rely on a younger, more athletic roster.

Referees and challenges

Coaches use the challenge rule to impact game flow. The league grants a second challenge opportunity if a team wins its first challenge. To request an instant replay review challenge, teams must use a timeout. The team loses a timeout when they use this second challenge regardless of whether the challenge succeeds. Successful challenges reached a 61% rate as of February 2025. Because the league allows referees to call a missed foul that occurred in the vicinity of an out-of-bounds play, the uncertainty of challenge outcomes increased for many coaches. Assistant coaches often review replays on a tablet to provide recommendations to the head coach. This decision must happen within a 5 to 15 second window before the official proceeds with the next game action.

Challenge Type	Success Rate
Out-of-bounds	76.5% to 79.0%
Goaltending	66.7% to 74.1%
Foul calls	52.4% to 52.7%

The success rate for challenges declines as the game progresses. The rate reaches 68.5% in the first quarter, 64.8% in the second quarter, 65.6% in the third quarter, and 51.8% in the fourth quarter. In overtime, the success rate drops to 42.9%. Only 12% of challenges occur in the first quarter, while 39% occur in the fourth quarter.