this is surely related to your tactics as I have scored 40+ each with Lavezzi and Torres multiple times. Are you attempting to play all 3 of those guys at the same time?
You need to provide us with more information on your tactics. Those three should not be utilized in a front line at the same time. Torres or Drogba would be out of place and the whole team would suffer as a result.
Paeotoja's answer is useless if you dont understand tactics. Lowering or increasing tempo, or messing with their freedom is a waste of your time if you dont understand the bigger picture.
Dropping them wont be the answer either. If you have played a whole season (like you suggest) then its not their "form". Torres and Lavezzi are two of the best in the game, Lavezzi can play on either wing as a winger or an inside forward, as a deep lying striker, or as a poacher. Torres can play on the right wing (i've never tried the inverted winger role for him on the left), as an advanced striker, a target man, or a poacher. Using Kofloks Goals Galore tactic Torres led the league in assists, goals, rating, and key passes for 3 years playing as an advanced forward.
The point is they can do anything you want them to provided your tactics are ok. Since they are underperforming, logically it must be the tactics...