Vincent Kompany sat on the sidelines with an ice pack strapped to his leg
Former Manchester City captain Vincent Kompany suffered an injury in Anderlecht's 1-0 defeat by Genk.
The centre-back could be a doubt to play in his testimonial which takes place at Etihad Stadium in three weeks.
Kompany, who joined Anderlecht as player-manager this summer, was treated on the sidelines before strapping an ice pack to his right leg.
He is due to return to Manchester on 11 September to celebrate 11 successful years at City.
On Thursday, Kompany relinquished his managerial duties on match days in order to concentrate on playing and instead took over the captaincy.
But the Belgian side have picked up just two points out of a possible 15 in their first five games - extending their worst start for 21 years.
Tanzanian striker Mbwana Samatta's 55th-minute goal was enough to give Belgian champions Genk their third victory of the season.
Anderlecht's starting XI included Kompany's former Man City teammate Samir Nasri and on-loan centre-back Philippe Sandler.
2de NorreSubstituted forMaehleat 79'minutes
19PiotrowskiSubstituted forHrosovskyat 72'minutes
11PaintsilSubstituted forNdongalaat 89'minutes
4KompanySubstituted forCobbautat 75'minutes
34SandlerSubstituted forKanaat 68'minutesBooked at 90mins
19ChadliSubstituted forAdzicat 73'minutes