Crouch was part of the England squad for the finals in 2006 when Walcott, at the time a 17-year-old with no Premier League experience, was a shock inclusion.
The Arsenal man did not feature in Germany and was left out altogether four years later for the tournament in South Africa.
And the cruciate damage suffered during Saturday's FA Cup victory over Tottenham means Walcott must wait another four years to play at a World Cup.
Stoke striker Crouch, interviewed by Sky Sports News for the Weekend Warm-Up programme, said: "I'm gutted for Theo.
"He was an absolute banker to go to the World Cup and possibly start. Having experienced World Cups they are the pinnacle, really.
"They're fantastic to be a part of, so obviously I do feel sorry for him and I wish him a speedy recovery.
"Maybe Arsenal have ruled him out completely, but I think he'll have some hope and if he's got a chance he'll be trying, but if he is ruled out obviously it's a bitter blow."
Watch the full Peter Crouch interview on Friday's Weekend Warm-Up from 6pm on Sky Sports News. The programme also includes an extended interview with Manchester United's Michael Carrick and Manchester City's Samir Nasri.