At the end of the season he moved to Geneva to play for Servette FC of the Swiss Challenge League.

Hassli left to join FC St. Gallen of the Swiss Super League, a club in the very east of Switzerland.

Hassli attracted the attention of plenty of clubs and returned to France to play for newly promoted Valenciennes in Ligue 1 during the 2006–07 season.

On 4 March 2011, Hassli signed with the Vancouver Whitecaps FC of Major League Soccer as the team's first designated player.

[3] Swiss media reported that Hassli was granted an early contract termination by FC Zürich, allowing him to leave on a free transfer to Vancouver.

[5] In the Whitecaps' 11 June 2011 match against the Seattle Sounders, Hassli scored two goals: the first from the penalty spot; the second a volley from an apparently harmless position on the right edge of the 18 yard box that flew into the top left hand corner.

[8] On 20 July 2012, Hassli was traded from the Whitecaps to Toronto FC in exchange for a first-round pick in the 2014 MLS SuperDraft and an international roster spot.

[15] On 2 December 2014, Hassli made his only appearance for indoor squad Las Vegas Legends against Ontario Fury in the Major Arena Soccer League (MASL).