One of the mistakes some managers make, is that they don’t dare substitute their star players, even if it is crystal clear that their star player is under-performing. Case in point is the match Portugal – Chile June 28th 2017 (0-0) in the Confederation Cup 2017 where Sanchez had a very low football efficiency to start and where Sanchez had his football efficiency drop even further during the match. Nevertheless, Pizzi, the Chilean manager, substituted Vargas rather than Sanchez. Vargas’ his football efficiency was also dropping. Nevertheless, no matter how you look at it, Sanchez wasted more time and effort of his team mates and himself than Vargas.
If you look at all the matches Chile played in the Confederation Cup 2017, then you see how the football efficiency of both players declined during the match: