BOSTON (AP) – Boston Celtics forward Paul Pierce has an injury in his left foot that will keep him out for two to three weeks.

Pierce has a stress reaction – a swelling of the bone and the soft tissue surrounding it, team spokesman Jeff Twiss said Thursday.

Pierce will miss tonight’s game against Philadelphia and the five-game road trip that starts Tuesday in Denver.

Pierce said his foot started hurting after Saturday’s game in Charlotte. He felt pain again after Wednesday night’s 96-95 loss to Golden State in which he scored 27 points and had an MRI on Thursday morning.

The Celtics are already without guard Wally Szczerbiak, who has a sprained right ankle and could return for the road trip. Forward Brian Scalabrine missed the Warriors game with the flu.