SYDNEY has conceded premiership defender Jarrad McVeigh could now miss multiple games at the start of the season with a "nasty" calf injury.

Swans football manager Tom Harley said the club did not have a return date for the 31-year-old, who suffered the grade two strain at training.

"It is a bit of a nasty calf and he won't be playing at the start of the season," Harley told the club's website.

"An exact return date, it's a bit hard to pin down, but he won't be playing in the first couple of weeks.

"As we know he's a hardened pro and he's doing everything he can to get back as quickly as possible."

Harley said the injury was to a load-bearing part of the calf and included some damage to tendons.

The Swans start the season against Port Adelaide on March 25 before a Grand Final rematch against the Western Bulldogs at Etihad Stadium.