Horford has been ruled out for Tuesday's game against the Jazz due to a left big toe sprain, Marc D'Amico of the Celtics' official site reports.
Horford will take a seat for the second night of a back-to-back set after posting 11 points, four rebounds, four assists, three blocks and one steal in 30 minutes as a starter during Monday's 121-99 win over the Trail Blazers. His absence is likely just precautionary, as the veteran has routinely sat out the second leg of back-to-back sets all season. Even so, Boston's frontcourt will be shorthanded Tuesday, as Kristaps Porzingis (hamstring) is also out.