McCormack said: “He’s been thinking about that for a while.
“He captained us at the last World Cup and knows exactly what we’re about.
“Any coach, World Cup or club, wants the best players to pick. Danny’s been a great servant to Scotland for near on 10 years. He’s put his hand forward, played exceptionally well and been an ambassador for us on and off the field.
“I’ve kept in touch with Danny for quite a few years now and certainly over the last 12 months and for him to put himself available is fantastic.
“When we start selecting that squad, to have someone like him available is superb for us.”