The 25-year-old forward is expected to need six months to recover, meaning he could miss at least four months of the season. Vegas plays its first game of the regular season against the Seattle Kraken on Oct. 12.
"With any recovery at that length, there's a lot of variables that may change. He'll rehab in Vegas under the care of our doctors," Golden Knights general manager Kelly McCrimmon said. "We expect him to recover well. He won't be with us in the early stages into the season, well into the season, in fact.
"It's a shoulder injury that's not uncommon to hockey players. It gives us more comfort knowing it's going to be a full recovery, but it is going to take time."
Tuch scored 33 points (18 goals, 15 assists) in 55 games last season and nine points (four goals, five assists) in 19 Stanley Cup Playoff games. The Golden Knights lost to the Montreal Canadiens in six games in the Stanley Cup Semifinals.
"The injury isn't traced to a specific incident," McCrimmon said. "It was an issue where his shoulder was giving him trouble through the year. When the season ended, no one anticipated it was going to be real serious or need surgery. Alex went away for a week, thought it would settle down during that period of time. (He) got back to Vegas and it was still bothering him. When we did the diagnostics, it was pretty clear he had an injury that needed to be surgically repaired. It wasn't an injury that anyone of us expected to have this outcome. It wasn't an injury that hindered his play in the playoffs."
Selected by the Minnesota Wild in the first round (No. 18) of the 2014 NHL Draft, Tuch has scored 139 points (61 goals, 78 assists) in 255 regular-season games with the Wild and Golden Knights, and 33 points (19 goals, 14 assists) in 66 postseason games.
