The Sharks also issued qualifying offers Monday to restricted free agents forwards Matt Nieto and Ryan Carpenter and defenseman Dylan DeMelo. San Jose will retain negotiating rights with the four players.
Hertl had 21 goals and 25 assists last season when he thrived on the top line with Joe Thornton and Joe Pavelski. Hertl hurt his right knee in the Stanley Cup Final, but is expected to be a key part of the team again next season.
The Sharks did not make offers to forwards Chris Crane, Petter Emanuelsson, Jeremy Langlois and Jeremy Morin; and goalie Joel Rumpel, making them unrestricted free agents.