However he then needed an operation after suffering the injury in a Top 14 match against Bayonne, which ruled him out of the whole of the RBS 6 Nations.
In his absence it was Toulouse winger Yoann Huget who was shifted to full-back, performing admirably in what was a difficult tournament for les Bleus.
Expected to return for Castres' clash with Perpignan this weekend, Dulin will instead sit that one out, and taking advantage of a week off for European games to return on April 13th against Bordeaux-Bègles.
He said: "I preferred to take an extra week. There will be the break and that will mean I'll have three weeks of training before Bordeaux come here."
Meanwhile, there was better news for Clermont scrum-half Morgan Parra who returned to training on Monday having been out of action for a couple of weeks since being forced off in France's final RBS 6 Nations clash with Scotland at half-time.