Per TLN's Kyle Cushman, Roni Hirvonen, Axel Rindell, Mikko Kokkonen and Topi Niemelä are all eligible to sign amateur tryouts (ATO) with the AHL's Toronto Marlies and squeeze in some games in North America to end the season.
While it's unlikely that all of these players will come over, we may see a couple of them heading to North America to get an early feel for what the smaller ice surface is like and to begin working with Leafs development staff. I'd imagine that the name on this list that is most intriguing to Leafs Nation is 2020 3rd round pick Topi Niemela. It's worth noting that Niemela has already signed a 1-year contract extension to remain in Finland next season.
I'd imagine that Mikko Kokkonen will be one of the players coming over, given that Kokkonen recently signed his entry-level deal with the Leafs, though his contract does not begin until the 2022-23 seasonm so an ATO would still be required this season. The 21-year-old is a 3rd round pick by the Leafs in 2019. A defensive defenseman, Kokkonen is probably not going to turn any heads with his puck skills, but he is known as a bit of a play-killer who plays a strong positional game. He could be a real difference maker for the Marlies.
In addition, Pontus Holmberg, a 6th round pick by the Leafs back in 2018, is already under contract with the Leafs, so he would not be required to sign an ATO. Like Kokkonen, I'd imagine that we'll see Holmberg coming over to North America as well.
*Update - Axel Rindell has signed his entry-level contract with the Leafs*