Ulster flanker Marcell Coetzee was injured during his side’s victory over Zebre over the weekend.
The Northern Irish side beat Zebre 68-21 after scoring 10 tries to the Italians’ three at Kingspan Stadium.
It was a spectacular performance from Les Kiss’s men but it came at a costly price after losing Coetzee in the 18th minute after injuring his knee.
The Springbok flanker only made his debut last month after being sidelined with a long-term knee injury for almost a year.
It is uncertain for how long he will be out for according to The 42 but Ulster will hope it will be short stint on the sideline as the flanker has made a huge impact since his return.