Ullrich return delayed

Ullrich has "a small twinge in the knee" and decided not to race in next week's Circuit de la Sarthe but will instead return at the end of April in the Tour of Romandy.
Is it a major setback?
I don't think so, It's true he never started his season so late, but he could still adjust his schedule to be prepared in time, maybe add tour of switzerland.
If he's knee is ok come tour de france time, my money is still on him.