Loof, 21, was drafted by the Blues in the third round (No. 88 overall) of the 2020 NHL Draft.
Loof has spent the last two seasons with Ilves of Liiga in Finland, posting 26 points (eight goals, 18 assists) and 58 penalty minutes in 103 games.
The Karlstad, Sweden, native also appeared in six games with Sweden at the 2022 World Junior Championships, earning a bronze medal.
