Boston Celtics forward Al Horford is unsure if he will play against the Brooklyn Nets on Monday.

Horford was initially listed as probable against the Indiana Pacers on Friday, but the veteran forward eventually played for the Celtics. The 32-year-old recently recovered from a knee injury, and the Celtics are taking a cautious approach in preparation for the 2019 NBA Playoffs.

According to Jay King of The Athletic, Horford said that he is still unsure about his availability on Saturday. King also confirmed that the five-time NBA All-Star will likely miss some of their remaining games in the regular season.

Horford had a productive night against the Pacers on Friday, as he finished with 19 points on 8-for-15 shooting from the field. He also posted seven rebounds, three blocks, and two assists for the Celtics in 35 minutes.

Boston escaped with a 114-112 win over the Pacers with Kyrie Irving leading the way with 30 points. Aron Baynes posted 13 points and 13 rebounds, while Jayson Tatum and Gordon Hayward posted 11 points apiece for the Celtics, who are still in a tight race for homecourt advantage in the first round of the playoffs.

The Celtics are currently fourth in the Eastern Conference standings with a 45-31 record. They are currently tied with the Indiana Pacers, and they still have a game left against each other.

Boston will face Indiana on Friday, which would be critical in the race for the fourth spot in the East. Aside from the Pacers, the Celtics still have games against the Brooklyn Nets, Miami Heat, Orlando Magic, and Washington Wizards, respectively.