Ricky Hatton has told BBC Sport he was surprised to see Amir Khan lose his WBA and IBF light-welterweight titles to Lamont Peterson in Washington DC, but is backing him to bounce back.
"It was a shock," said Hatton. "It's always a gamble to fight in your opponent's backyard but credit to Amir for doing that."
Hatton, however, believes Khan will recover from the setback.
"He is still one of our best boxers," said the former world champion.
Khan will formally question the performance of referee Joseph Cooper as well as the judges' scoring.
Cooper deducted two points from Khan for pushing, which proved crucial when the judges scores of 113-112, 113-112, 111-114 were announced in favour of the local fighter.
The 25-year-old said he felt like he was "fighting two people" after losing his titles, and he is likely to take Peterson up on his offer of a rematch.
Khan's camp are hoping to schedule the return for 31 March in Las Vegas, and Hatton believes a rematch is the right route to take.
"If I was Amir I would push for a rematch in my hometown, although that may be difficult," said former two-weight world champion Hatton.
"Unfortunately the gamble didn't pay off for Amir, but Peterson is a good fighter.
"Amir is still one of the best and if he needs my help in any way, shape or form I am there for him."