Arsenal striker Robin van Persie has broken the fifth metatarsal in his right foot, the club have announced.
Van Persie is Arsenal's leading scorer this season
Van Persie sustained a partial fracture celebrating his equaliser in Sunday's 2-1 win over Manchester United.
The 23-year-old, Arsenal's leading scorer this season, had an X-ray after the game, which confirmed the full extent of his injury.
It is likely the Dutchman, who had come on as a second-half substitute, will be out of action for at least six weeks.
Van Persie had been named on the bench after struggling to overcome an ankle problem but was sent on midway through the second half as Arsenal sought to overturn a 1-0 deficit.
And he brought his side level seven minutes from time when he converted Tomas Rosicky's right-wing cross.
Gunners boss Arsene Wenger fears his player faces a significant absence.
He said: "There is a big worry on Robin van Persie.
"He had scored a great goal because first of all Rosicky and Cesc Fabregas fought like mad for the ball, then they get it in and Robin comes from a very deep position and scores an unbelievable goal."