There are some reports he's had surgery on his knee on twitter. Havent seen any confirmation yet though.
Adam Leitch @adamleitchsport 7 minutes ago Gardos out for '6 or 7 months'. Koeman:“We have Stephens, we have Turnbull,but they are young and still have to improve themselves #saintsfc
6 or 7 months. Wow. That sucks. How did that happen. We'll be after two CBs now then I hope. Virgil and a loan maybe.
Gardos came on for Toby early on at Old Trafford when we won 1-0......thought he was superb that day. Has shown potential....lost the plot for a while at Stoke in League Cup...not finished article and injury is obviously a massive blow.