When Sinisalo started his ice hockey career in the 1970s, NHL teams did not scout extensively in Finland. The first Finnish ice hockey player in NHL was Matti Hagman for the 1976–77 Boston Bruins. However, NHL scouts were so impressed by Sinisalo's talents that they made an exception by signing him as a free agent after his 1980–81 season with HIFK, where he scored 27 goals in 36 games.
When Sinisalo embarked on his ice hockey career in the 1970s, NHL teams did not conduct thorough scouting in Finland. The first Finnish ice hockey player to join the NHL was Matti Hagman for the 1976–77 Boston Bruins. However, NHL scouts were so taken by Sinisalo's exceptional abilities that they made an exception by signing him as a free agent after his 1980–81 season with HIFK, where he scored 27 goals in 36 games.