He called for treatment three games into the match and resumed after having his ankle and foot heavily bandaged.
However, Roddick was clearly still in some discomfort as he served in the next game and decided to take the safety-first option with Wimbledon starting in just nine days.
Blake, who was a finalist here back in the 2006, admitted he did not take much pleasure from this victory.
"It was unfortunate but Andy is such a great player and he doesn't want to endanger the injury anymore," Blake said.The American will now try to stop Andy Murray who is bidding to become the first Briton to win the pre-Wimbledon warm-up event since 1938.
"He normally moves so well and you could tell this wasn't the same Andy Roddick."
Earlier, Murray completed a ruthless 6-2, 6-4 win over Juan Carlos Ferrero.
"I felt it was a good match. I started well but the second set was very close," Murray said.(Via cnn.com; Images by Julian Finney/Getty Images)
"I'm obviously happy to win in two sets. I was very happy with the way I played all round."
"I didn't have the easiest draw so it's been a good week all around and hopefully I can finish it off on Sunday."