Sep Vanmarcke's classics campaign hangs in the balance after the Belgian sustained a knee injury in a crash during stage five of Tirreno-Adriatico on Sunday.

The 24-year-old Blanco rider crashed in the neutral zone just outside of Ortona, rupturing the bursa in his right knee and forcing him to abandon the race.

On Monday tests in Belgium revealed that surgery will not be required, but he faces a race against time to be fit for E3 Harelbeke on March 22 and Gent-Wevelgem on March 24.

A Blanco team statement said: "Sep Vanmarcke will not have to undergo surgery on his knee after his crash in the Tirreno-Adriatico. The Belgian instead needs one week of rest. The chances he will be able to ride E3 Harelbeke and Gent-Wevelgem are 50 per cent. In Paris-Roubaix [April 7], Vanmarcke hopes to be in his best shape again."

Vanmarcke had been hoping to improve his record in the cobbled Classics, having won Omloop Het Nieuwsblad in 2012 and finished second in Gent-Wevelgem in 2010.

He tweeted on Sunday: "The only thing I'm hoping is that the classics aren't over. Last 5 months were all focus and dedication, and then this happens."