Belgian Tom Boonen crashed out of stage 1 at Paris-Nice on Monday and was diagnosed with a left acromioclavicular (AC) joint dislocation in his shoulder, after examinations were performed immediately at Centre Hospitalier in Blois.

His Etixx-Quick-Step team announced that recovery will take a minimum three to six weeks, precluding him from racing the Ronde Van Vlaanderen (Tour of Flanders) and Paris-Roubaix, coming up in April.

“An AC-joint dislocation, as we’ve already seen with other riders of the team with the same kind of injury, requires an extended time of recovery due to the nature of the injury,” Etixx-Quick-Step doctor Yvan van Mol said in a team statement. “Unfortunately, because of the injury and the time it takes to recover, Boonen will not be able to participate in the Northern classics.

“Tomorrow, Tom will undergo further examination in Belgium to diagnose the grade of the dislocation and determine if surgery is necessary based on the grade.”