Sterling expressed his displeasure after being left on the bench in the first round match against City, Maresca did not give him the opportunity to play even a few minutes, but he is not the only player who has faced such a problem. And this is not surprising, with such a depth of the squad there will always be unhappy players who will be left out of the game. I see this as a problem, because such a situation will lead to a lot of conflicts in the team, and I am almost sure that players like Sterling will not agree to sit on the bench, and will soon want to leave the team.
Sterling if he is not happy with the coach's decision not to play him in the match against Man City means he is not mature. Every professional player, no matter how old and experienced, must be prepared for the fact that he might not be in the squad on match day. That does not mean their future at the club is in question, or they should protest and leave the club. Every coach must have a strategy when facing an opponent, maybe at that time including Sterling was not the right choice.
As a senior player, he should be wise in seeing the coach's decision so that this does not cause conflict within the team. Sterling should go straight to the next match this season, and he must give a good first impression so that the coach will pay attention so that he can become the coach's main choice. Because no matter how good the coach is, if there is conflict within the team, it is not good for the next matches, let alone competing for the EPL league trophy.