Manchester City are looking good against Arsenal, but their title hopes might have been dealt a considerable blow on Saturday afternoon. Early in the second half, Sergio Aguero pulled up lame with no one around him and was forced to come off injured, with Jesus Navas replacing him.
Aguero scored City's opening goal in the game, his 13th of the season. That's good for second place in the league behind Luis Suarez, so as deep as City are up top, they're going to struggle to replace him if he's out for any kind of extended period of time.
Trainers were looking at Aguero's calf as he walked off the pitch gingerly, and he went straight down the tunnel instead of sitting down on the bench with his teammates to watch the rest of the game. City management and fans alike will be hoping he has just a bad pull, not a muscle tear.