Gambrell agreed to a two-year deal, and Suomela to a one-year contract. Financial terms weren't disclosed.
The 22-year-old Gambrell has failed to record a point in 11 regular-season games with San Jose, three in 2017-18 and eight last season. He appeared in two playoff games last season, scoring a goal.
Gambrell had 20 goals and 25 assists in 51 games last season for the San Jose Barracuda in the American Hockey League. The former University of Denver star from Bonny Lake, Washington, was selected 60th overall in the 2016 draft.
Suomela had three goals and five assists in 27 regular-season games for San Jose last season. The 25-year-old Finn had six goals and 14 assists in 47 games for the Barracuda. He signed with the Sharks as an undrafted free agent in June 2018.