Injured St Kilda captain Nick Riewoldt will have surgery on Monday to repair a right hamstring injury that is expected to sideline the forward star for two months.
Scans on Saturday revealed a high-grade muscle tendon injury.
Riewoldt is almost certain to miss up to two months, perhaps more, and his absence will be a blow to the club’s finals ambitions.
St Kilda said in a statement that the tendon had not come off the bone, however it was a “significant hamstring injury”.
The surgery will repair the damaged tendon but “does not involved the bone attachment”.
He hurt himself leaping for a mark just before half-time in Friday night’s 10.9 (69) to 4.17 (41) win over Collingwood.
Lyon pointed to the win as evidence the Saints could cope without their star forward, who was last year’s All-Australian captain.
Despite Riewoldt missing the second half and Justin Koschitzke not playing because of suspension, the Saints kicked six goals and kept the Magpies goalless after the long break.
“It’s going to be a challenge, no doubt about it,” Lyon said of the task of replacing Riewoldt.
“Let’s look at the facts, he’s a key forward, he’s pretty special.
“It’s going to be a challenge but we proved we can cope. We had 19 shots, kicked 4.3 in the last [quarter] when the game was up for grabs.
“Koschitzke will be back soon and we’ve got (Rhys) Stanley and (Michael) Gardiner’s a pretty good forward.
“We’ve got to improvise, but everyone else has challenges. Obviously it’s a significant one, but we’re looking forward to coping with it.”