Robidas signed for $9 million over three years, while Komarov returned to Toronto after a year in Russia's KHL to sign an $11.8 million, four-year deal.
Komarov's return could help replenish Toronto's forward depth after losing Dave Bolland, who signed a $25 million, five-year deal with the Florida Panthers. Komarov had four goals and five assists for the Leafs in the lockout-shortened 2013 season before going to play one year with the KHL's Dynamo Moscow.
His agent, Mark Gandler, said earlier in the day Komarov was looking for a significant role in coming back to the NHL and that teams were willing to give him that. The Leafs, who had his rights until July 1, opted to bring him back.
Toronto traded Frattin to the Los Angeles Kings in June 2013 as part of the deal for goaltender Jonathan Bernier. The Kings sent him to Columbus at the 2014 deadline as part of the deal that got them Marian Gaborik.
Frattin has 17 goals and 18 assists in 126 games. The Leafs also got a conditional seventh-round pick in 2015 as part of the trade.