The knockout phase of the UEFA Champions League is months away, but every game is critical for title contenders. If you look at the roster of clubs like Chelsea and Barcelona, you'll notice depth at various positions, where players will be able to afford an off-game or two.
Some clubs, however, have their future riding on one or two footballers only. These will be the key players to watch during the group stages, as they'll need to carry their clubs to the next phase.
Let's take a look at the players who will need to be at the top of their game throughout the entire group stage.