Although Toivonen was widely considered to be a top goaltending prospect, he was injured in 2005–06 and never regained the form that made him a first-round selection in 2002.

With Andrew Raycroft sitting out due to a contract dispute, Toivonen started the 2005–06 NHL season as the Bruins' backup goaltender.

Toivonen was 9–5–4 with a 2.63 GAA and a .914 SV% before suffering a high ankle sprain in January that effectively ended his season.

[2] Upon being traded to the Blues, Toivonen was reunited with former Bruins teammates Brad Boyes, Ryan Glenn, Yan Stastny and Derek Gustafson.

On 1 March 2010, Toivonen was traded from St. Louis to the Chicago Blackhawks, along with Danny Richmond, in exchange for goaltender Joe Fallon.

[8] On 11 April 2014, Toivonen returned to Finland to sign a contract with newly promoted Liiga club, Vaasan Sport.