Frenchman Nicolas Mahut, he of the 70-68 fifth-set marathon with John Isner at 2010 Wimbledon, was beaned in the head by a shot from his doubles partner in the French Open semifinals on Thursday.
Pierre-Hugues Herbert and Mahut recovered to beat Nikola Mektic and Alexander Peya 6-3, 6-4 to reach the final.
Mahut was hit 18 minutes into the match and left the court for a few minutes, according to Agence France-Presse.
Herbert and Mahut, seeking their third Grand Slam title together but first at Roland Garros, will play either the Spanish team of Feliciano Lopez and Marc Lopez or Oliver Marach and Mate Pavic in the final.