Addy was replaced in the 9th minute of their clash at Rejika in the match which ended 2-2.
Dinamo Zagreb run tests on his injury and confirmed the centre-back has damaged an anterior cruciate ligament.
Addy's season has ended and will spend six months in the treatment room.
"The review of the first diagnosis confirmed Addy has a subtotal rupture of the anterior cruciate ligament and tearing of the lateral meniscus of the left knee," Dinamo Zagreb doctor Ivica Smodek said.
The 23-year-old has been ruled out of the rest of the season and cannot be considered for selection by Ghana coach Kwesi Appiah.
He has been out of the Black Stars since June 2012 when he was named in the squad which lost 1-0 to Zambia in Ndola in a 2014 World Cup qualifier.
Addy has made 16 league appearances for the Blues this season and regarded a key player for the leaders.