2004-05: Kolosov opted to stay in Belarus even though the Red Wings hoped he would spend the year in the WHL. He played 37 games with Dynamo Minsk, scoring 2 goals and 6 assists for 8 points. He was held scoreless in 9 playoff games with Dynamo Minsk. Kolosov was apart of Belarus’ U20 entry to the World Junior Championships but was held scoreless in 6 games. It was still a strong performance for the hulking defenseman, who found success using his body against opposing forwards along the boards and in clearing the crease.
2005-06: Kolosov played for the USHL’s Cedar Rapids Roughriders in his first North American season. The defenseman scored 2 goals, 8 assists for 10 points in 50 games. He was held off the scoresheet in 8 playoff games. Kolosov again played for Belarus’ U20 team, this time in the Division I WJC tournament, and scored 1 goal, 4 assists in 5 games.
2006-07: In his second USHL season, Kolosov scored 1 goal, 10 assists in 51 games. He also added 79 PIMs to his totals. He went scoreless in 5 playoff games.
2007-08: Kolosov returned to his native country, Belarus, and his former team, Dynamo Minsk. In 47 games, the blueliner scored 4 goals, 6 assists for 10 points along with 73 PIMs.
2008-09: Kolosov played his first season of North American pro hockey with Grand Rapids in the AHL, scoring 4 goals, 7 assists for 11 points in 70 games.
2009-10: In his second season with Grand Rapids, Kolosov scored 2 goals, 6 assists for 8 points in 66 games. He represented Belarus in both the Olympics and World Championships, but was held off the scoresheet in each tournament.