Filip Krušlin started his professional career in 2007-08 season, touted as a hot prospect for Cibona's future. He was recognised as a young talent while he played for younger selections in Zrinjevac and Rudeš. His debut for Cibona came against Široki in 2007–08 Adriatic League season.[1] He played a total of 8 minutes and managed to gather up 4 points by getting a three pointer and one free throw scored. After that he played nine more games for Cibona in the Adriatic League. His season highlight was 7 points and 1 rebound in 10 minutes spent on court against Crvena zvezda.
At the start of 2008-09 season, Krušlin was offered a loan move to aid his development. Cibona has already signed five more guards that season which did not guarantee much play time for Krušiln. He was then loaned to another club from Zagreb, Dubrava. After suffering an injury and not playing in the Fall of 2009, he left Cibona and joined Dubrovnik. He spent a season at Bosna and Zabok before moving, in 2012, to Split.
On April 3, 2014, Krušlin signed a contract with Cibona.[2]
On July 26, 2016, Krušlin signed a three-year deal with Cedevita.[3]
On June 1, 2020, Krušlin signed a deal with Dinamo Sassari of the Italian League.[4] Initially he was not renewed for the 2021–22 season, but then, eventually in November, 2021, he was called again from Sassari to play for one more season.[5]