"It nearly did [catch up with him] against Luis Collazo [against whom Ricky Hatton won the WBA welterweight title] in his last fight but he scraped through.
"There is a danger he is going to lose to someone he wouldn't have a couple of years ago and that would change the whole picture.
"Mick Hennessy [Witter's promoter] is working on something and I'd like [the fight] to happen, but I'll just leave it in his hands.
"It's a fight everyone wants to see and I want it to happen so it's just a case of Ricky and [Hatton's trainer] Billy Graham sorting it out."
Bradford's Witter, 32, won his world title with a unanimous decision over DeMarcus Corley at Alexandra Palace in September.
It ended years of frustration for Witter, who lost his first world title bid against Zab Judah in 2000.
But Witter has not allowed success to go to his head and sacrificed the usual Christmas indulgence to prepare for the tough Mexican Morua.
"[After the match with Corley] I had a civic reception and got an award from Bradford Bulls," said Witter, the former British, European and Commonwealth champion.
"And I've been on the pitch at Bradford City, Rotherham and Doncaster Rovers.
"It's nice to get the recognition but I've had to get back into the groove.
"The hardest thing has been Christmas and New Year. You like to enjoy yourself, spend time with your family.
"There's a lot of booze and food about and everybody's offering something."
A win against the 28-year-old Morua, who has 24 wins from 32 fights, could lead to a mandatory defence against Juan Lazcano or Vivian Harris.
Mexico's Lazcano meets Guyana's former WBA title-holder Harris in a WBC eliminator on 10 February.