Coach Lindy Ruff said before the game that Sekera will miss at least a few days and potentially longer.
Sekera was hurt Saturday, when he was struck in the leg by Canadiens defenseman Alexei Emelin's shot in the first period of a 6-1 loss at Montreal. Sekera played a few more shifts before missing the final two periods.
The Sabres are already missing veteran defenseman Robyn Regehr (lower body), who will miss his fourth straight game. Ruff said Regehr is expected to return to practice this week.