Annunen stopped 23 of 27 shots in Friday's 4-3 loss to the Sabres.
Annunen had come out on top in each of his previous four starts. However, the 24-year-old netminder posted a save percentage below the .860 mark for the first time since Nov. 25. Annunen finished the month of January with a 4-1-0 record across five starts while posting a 3.02 GAA and an .894 save percentage.