The Ibrox legend, 58, is taking part in rugby great Doddie Weir’s campaign to fund research into motor neurone disease.
Doddie, 50, aims to raise £1million by February 6 when Scotland play England in the Six Nations opener.
Participants aim to clock up as many miles as they can through physical activity and stars including Gary Lineker, Lorraine Kelly and Sir Chris Hoy have signed up.
The stars have been split into five teams representing the former rugby districts of Edinburgh, Glasgow, South, North and Midlands and the Exiles, with the district who raises the most being declared winners.
Glasgow captain Ally has revealed Butler and teammate Kenny Logan have been tormenting him.
He said: “I’m getting savaged. I’m getting more stick as team manager of Glasgow than I did when I was manager at Rangers and that’s saying a lot. The stick flying about is unbelievable.
“I’m getting it from Logan down south, which I kind of expected, but when Gerard Butler starts piping in from Hollywood, I’m thinking this is incredible.
“If one of my duties is to buy and sell for the team then Butler and Logan will be on the list.”
Ally added: “The way Doddie and the family are handling the whole situation is absolutely remarkable.
“I’ve got connections with Fernando Ricksen as well and it is an absolutely horrendous illness.
“It is great that we can have a little bit of fun and enjoy ourselves out running, walking or cycling doing our little bit and every bit counts whether you’re cycling 50 miles or walking five miles it doesn’t matter because we’re all trying to do the same thing and that is help Doddie because I love him dearly.”
Former Scotland international Doddie was diagnosed with MND in 2016 and has helped raise more than £7million for research.