David Moyes has challenged Lamine Kone to become a leader for Sunderland after the Ivory Coast defender was made one of the highest paid players in the club's history.
Kone this week pledged his future to Wearside after signing a new five-year contract worth £90,000-a-week.
The 27-year-old was strongly linked with a move to Everton last month, but Moyes blocked a proposed £18m switch in order to keep hold of the centre-back, who played a major role in Sunderland's successful survival bid last season following a £6m move from Lorient in January.
The Scot now wants Kone to prove his commitment and justify his hefty pay rise by helping lead the Black Cats' latest Premier League survival bid, one which suffered another setback with Monday's comprehensive 3-0 home defeat by Ronald Koeman's side.