This still is the moment just before Kouyate takes the ball by Yaya. As he kicks the ball Otamendi steps out leaving a gaping hole behind him.
Look at Kouyate, what options has he got?
1. Kick it and run - Yaya should win that ball back or at worst clear the ball.
2. The player just to his right - not really an option is it?
3. The player on the left wing - closely marked by Sagna, we win possession back.
4. The ball into Valencia's feet - Delph can cover the run but only Otamendi can win possession back by intercepting the pass.
In everyone of those situations we win the ball back or at worst clear it for a throw in or corner, if Yaya does his job. That's the strategy Pellegrini wants us to play, anyone who watches us knows we defend on the front foot and knows our defenders try to win the ball aggressively (over aggressively) at times. Under Mancini, Otamendi would have been told to hold his position and cover Yaya but that's the risk we take.