Alnefelt, 19, has appeared in 22 games with HV71 of the SHL in Sweden, posting a 5-16-0 record to go along with a 3.16 goals-against average and .904 save percentage. The 6-foot-3, 187-pound goaltender also represented Sweden at the 2021 World Jr. Championships, posting a 2-2-0 record with a 2.36 goals-against average and .902 save percentage. He has represented Sweden at each of the past two World Jr. Championships, winning the Bronze Medal in 2020 while posting five wins at the tournament.
The Danderyd, Sweden native has played in 40 games with HV71 over the past two seasons, registering 15 wins, a 2.89 goals-against average and .904 save percentage. Alnefelt has also appeared in 32 games for HV71 J20 SuperElite over the past three seasons, earning a record of 19-12-0 to go along with a 2.72 goals-against average and .902 save percentage.
The Lightning selected Alnefelt in the third round, 71st overall, at the 2019 NHL Draft.