Racing UK, which is sponsoring the Grand National and Cheltenham Gold Cup winner for 12 months, was due to feature a fit Walsh in a campaign spanning press ads, inserts and 50,000 mailings this week.
The strapline was intended to be "Take an armchair ride with Ruby".
Racing UK's agency BPL Marketing has changed the picture in the ads to one of Walsh with his leg in a cast.
The ads still read, "Take an armchair ride with Ruby" but will now also state "Put your feet up and enjoy top class Jumps racing on Racing UK".
Consumers are also encouraged to visit Racing UK's website, where they are invited to send their best wishes to Walsh, who is out of racing for 12 weeks.