The average annual value of the deal is $8,137,500, a source told ESPN's Greg Wyshynski, and it includes a no-move clause for the first three years and a limited no-trade clause in the other five.
"Tomas has evolved into a premier top-line centerman in the league, competing against the NHL's best players every single night and delivering significant results," assistant general manager Joe Will said in a statement Wednesday. "There are few centermen in the NHL with his combination of physical and dynamic play and he is a player that you build a franchise around. We are fortunate to have two of the league's top centermen on one team with Tomas and Logan Couture.
"By agreeing to this contract, Tomas is cementing his path with the Sharks, following in the footsteps of some incredible players who have worn the Sharks crest. He has shown that he wants to play in San Jose for years to come and it shows his dedication to the organization and community since he joined the team in 2012. We are thrilled to have Tomas for another eight years."
Hertl was in the final season of a four-year, $22.5 million deal. He had been the subject of trade rumors for weeks leading up to Monday's deadline, but San Jose had been adamant about trying to come to an agreement that locked Hertl up long term.
The Sharks selected Hertl 17th overall in the 2012 NHL draft, and he has grown into the franchise's top-line center. Since his breakout 74-point season in 2018-19, Hertl has been the new face of the franchise.
Born in Prague, Czech Republic, he had said publicly he wanted to stay in San Jose and was only looking for a "fair deal" out of negotiations with the Sharks. San Jose has been hampered in recent years by long-term deals attached to players now into their 30s (some of whom have also declined on the ice), making its salary-cap situation difficult to navigate.
San Jose has Marc-Edouard Vlasic under contract until 2026 at $7 million per year, Erik Karlsson locked in until '27 at $11.5 million per, Brent Burns until '25 at $8 million per and Logan Couture until '27 at $8 million annually.
While it didn't seem like adding another max contract to the mix would work, in the past few days, Hertl and the Sharks began finding a way toward keeping him in the fold.
"I think we've got some good young guys," Hertl said this week. "I don't think we've had this many in the past. Hopefully, they can come and play. At the same time, you can't hurry and just put them in the top positions if they aren't ready."