5-2 but dropped the pairís last meeting 3-6, 6-4, 7-6(7-1) last year in the semifinals at Indian Wells.
Monte Carlo is the first major ATP Tour warm-up tournament for the French Open, which begins May 22nd in Paris.
Federer scored his lone French Open singles title in 2009.
Nadal, a much more accomplished clay court player then his Swiss rival, won his fifth Paris title last year to post a career Paris record of 38-1. The Spaniard is considered by many to be the greatest claycourt player of all time.
Nadal has won 33 matches in a row at Monte Carlo; having lost only one match ever in the city in 2003.
Head to head, Nadal leads Federer 15-8. In their last meeting last month month, Nadal topped Federer 6-3, 6-2 in the semifinals at Miami.