Luukkonen has not played since Games 1 and 2 of Buffalo’s first-round series against the Boston Bruins last month.
Across the two playoff games, he recorded a 4.19 goals-against average and .825 save percentage.
Alex Lyon, meanwhile, has started Buffalo’s eight other playoff games this season, posting a 2.18 goals-against average and .921 save percentage.
However, the changes for Buffalo don’t end in the crease.
Schenn, the veteran defenceman, joined the Sabres in a mid-season trade from the Winnipeg Jets and appeared in four games with the Atlantic Division club, failing to record a point. He had one goal and six assists in 47 games with the Jets.
The 36-year-old is a two-time Stanley Cup champion, winning his titles with the Tampa Bay Lightning in 2020 and 2021. In all, the blueliner has 58 playoff games under his belt.
Helenius, 20, will get his first taste of playoff action after making his NHL debut this season, recording one goal and three assists over nine games.
The 14th overall pick in the 2014 draft spent most of the season in the AHL, where he tallied 21 goals and 41 assists in 63 games.
The Sabres won the first game of Round 2 but lost the next two by scores of 5-1 and 6-2.
