Craig Noone will miss the start of the season but hopes to be back as soon as possible.
Ole Gunnar Solskljaer said: "It's good news about Craig, but we won't rush him back."
Noone suffered a recurrance of an injury he suffered last season when he took part in Cardiff's opening pre season game against Carmarthen.
It's hoped he will now be available to play in the opening six weeks of the season.