There is not a lot of time for the Boston Celtics to prepare for the second round of the playoffs against the Philadelphia 76ers, as their first-round series with the Milwaukee Bucks went the distance. What that also meant is that Celtics forward Jaylen Brown has little time to fully recover from a hamstring injury he sustained during Game 7 of the Bucks series.

Brown has been ruled out tonight and Marcus Smart will start in his place.

Brown’s injury adds to the health woes of the Celtics, who are already dealing with the absence of Kyrie Irving and Daniel Theis. Should Brown sit out Game 1 against the Sixers, it’ll take away from the Celtics a key component to their playoffs success thus far.

Jaylen Brown is the second leading scorer for the Celtics this postseason, averaging 17.9 points on 46.7 percent shooting from the field in seven games. In the series-clinching win over the Bucks last Saturday, he was only able to play for 16 minutes, finishing with just two points, an assist, a rebound, and a steal.

Inserting Marcus Smart to the starting lineup in lieu of Brown would mean a smaller lineup for Boston, which enters Monday’s showdown with Philadelphia looking to extend its five-game win streak at TD Garden.

The Celtics have also won seven of their last 10 home games against the Sixers.