The biggest worry for the Celtics rests in one surprising place

The Boston Celtics know they will have to worry about Kristaps Porzingis' health over his next two contracted seasons. The Latvian big man was a sporadic presence during Boston's Banner 18 run, and he'll be out until 2025 due to surgery for the dislocation of his posterior tibialis tendon.

But the biggest worry for the Celtics is actually something else: Al Horford will be worn down during the 2024-25 season, his last under contract, and be bent out of shape by the time the postseason rolls around.

Kristaps Porzingis injury puts Al Horford in danger of playing too many minutes

Horford has been playing starter minutes under Joe Mazzulla in the postseason, over 30 minutes per game during the 18-game 2024 championship postseason and the 19-game 2023 playoff run that was cut short by the Miami Heat in the Eastern Conference Finals.

He's shown few signs of slowing down, but as each calendar year passes, especially the duration of this next campaign, given his contract status, Father Time is catching up, and retirement is making more sense.

Horford playing big minutes early in the season should be a last resort, but it's worth noting that Boston's second-unit bigs were part-time bit players, at most, during the 2024 NBA postseason.

Mazzulla may need to rely on Horford too much if Xavier Tillman and Luke Kornet fail to help the Celtics effectively sustain their league-best pace from last season. A Mazzulla-led team relenting on the gas pedal feels like an improbability unless losing Jeff Van Gundy and Charles Lee from his coaching staff is a more significant pitfall than expected, but playing Horford big minutes could prove to be too necessary.

For however long Horford has left in Boston, he may have to be the part-time starter to account for Porzingis' injury woes. The C's aren't going to trade Porzingis with his contract and importance to the team. Horford is the only other starting-caliber big on the roster right now.

Mazzulla is banking on Tillman making a leap in 2024-25 or Kornet finally becoming the rim protector his size puts his ceiling at. If neither happens, the Celtics have a Horford problem that could threaten their Banner 19 chances.