The body takes time to adapt.
Yea pitches are playing a big part
Extra running in games increases load
New training methods under a new manager
Also when the pitches cause a few injuries the players that are fit get over played and an injury crisis occurs.
To add to that when they were close to the league they played Daniel "Stir-itch" injured. And he's been ruined since.
Its not the first time theyve done this to a striker, I've never seen a player flogged to death more than Torres at Liverpool.