In 2010, Alhassan signed with Portland Timbers of the USSF Division 2 Professional League, in hopes of staying with the club in 2011 for their inaugural season in Major League Soccer, the top tier of the United States soccer pyramid.

[1] In his first start for the Timbers, Alhassan scored in second-half stoppage time to give Portland a 1–0 victory over Puerto Rico Islanders.

[2] In 2011 Alhassan became the third player in Major League Soccer history to open his career with assists in each of his first three home games, all Timbers wins.

On 17 December 2015, Alhassan was released by Minnesota and picked up by the Tampa Bay Rowdies.

Kalif is the son of former Ghana international and two-time Africa Cup of Nations winner George Alhassan.