Cameron Carter-Vickers and Reo Hatate will both miss out this weekend against Kilmarnock as Brendan Rodgers confirmed the pair remain on the sidelines with injury.
Celtic aim to maintain their domestic domination as the Irishman reacquaints himself with old rival Derek McInnes and a Kilmarnock team which has impressed with a win over a Rangers and a draw with Hearts at Tynecastle.
And now the holders head to Ayrshire as they seek to plot another route back to second home Hampden. But they'll have to do it without key pair Hatate and Carter-Vickers who won't be able to play.
When asked for an update ahead of Sunday's last 16 clash at Rugby Park, Rodgers said: "They're not available for this weekend so we just have to assess them and see how they are.