Patrick Marleau scored the only goal of the shootout, lifting the San Jose Sharks to a 2-1 victory over the Washington Capitals on Tuesday night.
Tomas Hertl scored four goals, Matthew Nieto had his first NHL goal and added two assists and the San Jose Sharks beat the New York Rangers 9-2 on Tuesday night.
General manager Doug Wilson announced the deal Thursday. Demers is the third potential restricted free agent signed this week by the Sharks, joining forwards James Sheppard and Andrew Desjardins.
Jason Demers scored his first NHL goal and Antti Niemi stopped 23 shots for the Sharks, who have lost six of seven.
Joe Thornton scored the tiebreaking goal in the second period of his 500th game with San Jose and the Sharks went on to beat the Columbus Blue Jackets 2-1 on Thursday night for their third straight win.
Antti Niemi made 34 saves for his first shutout of the season and Jason Demers broke a scoreless tie late in the second period to lead the Sharks to a 1-0 victory over the Blackhawks Wednesday night.
Joe Thornton scored 2:22 into overtime Monday night to give San Jose a 4-3 victory over the Los Angeles Kings and send the Sharks to a first-round series win.
Ryane Clowe scored two goals, Jason Demers added another in the second period and the San Jose Sharks beat the Los Angeles Kings 6-3 on Thursday night.
Dany Heatley scored 14 seconds in, Ryane Clowe had a goal and an assist, and the San Jose Sharks hung on to beat the Anaheim Ducks 4-3 Wednesday night for their second straight win after the All-Star break.
Logan Couture and Ryane Clowe scored shootout goals to give San Jose a 5-4 victory over Philadelphia on Wednesday night after the Sharks overcame a three-goal, third-period deficit and an apparent Flyers goal in the final second of overtime.