MotoGP stars Valentino Rossi and Marc Marquez will be following Fernando Alonso's upcoming Indy 500 debut with great interest and have tipped the Spaniard to be "really fast" in the iconic oval race.
Alonso is missing the Monaco Grand Prix to drive at the Indianapolis Motor Speedway on May 28 in a McLaren entry powered by Honda and run by Andretti Autosport. The Spaniard will race with just two weeks' worth of practice and a private test at IMS on May 3, taking place between the F1 races in Russia and Spain, to his name.
Seven-time MotoGP champion Rossi -- who tested a NASCAR stock-car at the Charlotte Motor Speedway in 2013 -- thinks Alonso has a big challenge ahead of him.