Ghanaian defenders Abdul Mumin Suleman and Gideon Mensah will miss Vitoria Guimaraes' trip to Clube Desportivo Nacional on Monday night.
The pair are missing the game due to injuries.
Abdul Mumin Suleman is struggling with trauma to the left knee with Mensah out with myalgia in the left thigh.
Their absence is a huge blow for manager Joao Henriques, who has been very reliant on the duo throughout the campaign.
They are expected to recover in time for the game against Morereinse on Friday.
Mensah is on loan from Austrian giants and has made 19 Primeira Liga appearances for the Portuguese giants.
Abdul Mumin who joined in the summer transfer window from FC Nordsjaelland has made 22 appearances for the club.