Hertl had surgery on his right knee and missed 43 regular-season games after his collision with Brown. He injured his right knee again in Game 2 of the Stanley Cup Final in 2016 and missed the final four games of the series, which the Sharks lost in six games against the Pittsburgh Penguins.
Then, on Nov. 11, 2016, Hertl injured his right knee a third time during a game against the St. Louis Blues and needed surgery. He was out until Jan. 1, 2017.
Hertl spent last summer strengthening his knees and preparing his body for this season.
"I had a great three, four months," Hertl said. "I had a long summer. I worked really hard. I have to do some extra stuff for my knee still. Probably I will all my life, because I want to make sure I'm strong and nothing happens again."
The Sharks selected Hertl (6-foot-2, 215 pounds) with the 17th pick in the 2012 NHL Draft. He made his debut at the age of 19 and appeared headed for a 30-goal rookie season before the injury.
Two years ago, Hertl scored six goals and had 11 points in 20 playoff games before a hit by Penguins forward Patric Hornqvist ended his season.
"Injuries happen in this game," Sharks forward Logan Couture said. "Unfortunately, it's happened to him quite often over his career. It does hurt the team and him. This year, everyone saw what he's capable of. He's a very talented player. He's big, he's strong. That size and that skill, you really can't teach that. When he's playing well, he's holding onto pucks and he's strong and he's tough to play against. He's been great for us."