The Chelsea left-back - who is currently on loan at Schalke 04 - was stretchered off during the first half of his country's clash with Uganda at the Africa Cup of Nations, and the Ghana Football Association has suggested that the player will need to undergo surgery on the injury.
A statement read@: "Ghana defender Baba Abdul-Rahman will travel to Germany today (Thursday) to undergo further tests and possible surgery over a knee injury he suffered at the 2017 Africa Cup of Nations in Gabon.
"Ghana Football Association (GFA) took the decision in consultation with his club Schalke after tests were carried out on the injury in the Gabonese capital of Libreville on Wednesday.
"The Ghana medical team led by Dr. Adam Baba revealed that the defender suffered 'a rupture of the meniscus and a particular tear of the anterior cruciate ligament with fluid collection in the left knee'."
Rahman made 23 appearances for Chelsea last season before being allowed to spend the year in the Bundesliga with Schalke.