Tiago Monteiro will drive OAK Racing's Pescarolo-Judd LMP1 car at Le Mans in place of the injured Matthieu Lahaye.
Lahaye sustained back, hand and knee injuries in a qualifying crash in the Intercontinental Le Mans Cup/Le Mans Series event at Spa earlier this month, leaving a vacancy in OAK's Le Mans line-up alongside Guillaume Moreau and Pierre Ragues.
World Touring Car Championship frontrunner Monteiro last contested Le Mans in 2009 with ORECA.
OAK's managing director Francois Sicard said: "As a driver and personality Matthieu is difficult to replace, but we see Tiago's arrival as a significant positive [as he] shares many of the same attributes.
"Throughout his career Tiago has always been as popular on the human side as he is sporting. He is a remarkable driver, fast, reliable and a very engaging person true to the spirit of endurance racing.
"This arrival offers a real boost to the team, which really needed one at this difficult time."