The 27-year-old could only watch from afar as back-rowers Ben Morgan, Chris Robshaw and Tom Croft helped England secure second place in the Championship.
But he insists his recent travels, which also include a stint playing for the Highlanders in New Zealand, have benefitted his game and he's more ready than ever to try and win back a place in Lancaster's first XV.
"The squad is in a great place and, under Stuart Lancaster and Graham Rowntree, it has returned to a level where players are desperate to be involved and fans are proud to shout support," said Haskell.
"Guys like Chris Robshaw and Ben Morgan to name a few have set new back-row benchmarks in that white shirt.
"But I want to fit into that environment, essentially as a 'new boy', and earn the right to play a part.
"Taking the risk of ruling yourself out of contention for England is always a difficult pill to swallow, but my experiences in the last year, in Japan and now in New Zealand have been second to none. I have developed as a player, both on and off the field.
"This said, however excited I was about England's performances in the Six Nations from a fan's point of view, it didn't make up for that little bit fear that I may never put that white shirt on again and represent my country.
"But it's always an amazing honour to be asked to join the England squad, especially when the quality of competition is so high.
"For all that my critics say, the reason I play rugby is to play for my country."