Liverpool went behind on the brink of half time after a slip by Gerrard allowed Demba Ba to pick up the loose ball, run through on goal and finish past Simon Mignolet.
Torres fostered a close relationship with Gerrard during his four years at Liverpool between 2007 and 2011 and was hurt to see his friend’s misfortune.
"I felt so sorry for Stevie,” he told the BBC’s Football Focus programme. “We didn't have chances to win the Premier League and Liverpool were so close.
“And I know how important it is for Liverpool to win the Premier League after so many years and it was so unfair for Stevie.
“He was the person who really deserved to win the Premier League, but that's football. In one second everything changed.”
Chelsea’s win that day was rounded off by Willian in the fourth minute of added-on time. Torres himself could have administered the coup de grace after going through one-on-one on Mignolet, but instead chose to lay the ball off to his Brazilian team-mate.
When asked why he had not taken a shot at goal for himself, Torres, who sits 20th in Liverpool's all-time scoring ranks, simply said: “I had a team-mate next to me in a better position.”
Torres also hailed Gerrard as the best player he has played with throughout his career, telling Football Focus: “He is everything I needed on the pitch altogether in one player.
“I was a big fan of Stevie before I went to Liverpool but playing with him was much better than I was expecting. It was amazing, by far the best player I played with and I would pay to play with him again.”