In 535 career NHL regular-season games with the St. Louis Blues and Maple Leafs, Polak has accumulated 19 goals and 82 assists for 101 points, to date, along with 423 penalty minutes.
The native of Ostrava, Czech Republic, was originally drafted by the Blues in the sixth-round, 180th overall, of the 2004 NHL Entry Draft.
Spaling, 27, tallied one goal, six assists and 18 penalty minutes in 35 games with the Leafs this season.
In 414 career NHL regular-season games with the Nashville Predators, Pittsburgh Penguins and Leafs, Spaling has accumulated 50 goals and 68 assists for 118 points, to date, with 114 penalty minutes.
He was originally selected by the Predators in the second-round, 58th overall, of the 2007 NHL Entry Draft.
"Roman and Nick are both quality, character players that will complement and enhance our current roster," said Sharks GM Doug Wilson. "Our existing group of players has battled hard and they have earned the right to have every chance to succeed this season."
Torres, 34, has gone pointless in six games with the Sharks' affiliate affiliate, the San Jose Barracuda, this season.
In 635 career NHL regular-season games with the New York Islanders, Edmonton Oilers, Columbus Blue Jackets, Buffalo Sabres, Vancouver Canucks, Phoenix Coyotes and Sharks, Torres has picked up 137 goals and 123 assists for 260 points, with 497 penalty minutes.
The Toronto native was originally drafted fifth-overall by the Islanders in the 2000 NHL Entry Draft.
The Leafs have re-assigned Torres to the Barracuda.