Juventus striker Cristiano Ronaldo left the stadium early after being hooked in victory over AC Milan.
Paulo Dybala replaced Ronaldo on 55 minutes - and scored the winning goal.
But Ronaldo was visibly upset by his substitution, muttering something at coach Maurizio Sarri before walking straight down the tunnel.
Sky Italia reports he then left the stadium - three minutes before the end of their 1-0 victory.
Ronaldo was also substituted against Lokomotiv Moscow midweek.
