Scotland's new national coach Craig Levein says no player will be ruled out of his future plans.
The previous regime saw Rangers striker Boyd refuse to play under George Burley's management, while Ferguson and McGregor were both banned for life in the wake of the 'Boozegate' affair.
"I will not be ruling out any players.
"Whether those players, when selected, don't want to come, then that's a different matter.
"My job's to try to qualify (for Euro 2012), so I'll be picking the best players.''
Levein said he was encouraged by Ferguson's comments he would consider a return to international football, adding: "We're not a big nation. We need every top-quality player.''
Qualifying for those European finals in Poland and Ukraine is Levein's immediate aim and he spoke of restoring "pride and passion" to the national team.
"I think there is a malaise around the game just now,'' he said. "I think we need to change some attitudes more than anything else.
"We need to be a bit more positive in what we are doing, have more pride and passion.
"I've been working hard for around 15 years in management and now I have the opportunity to make a significant difference, not just to the Scottish national team but to the way people feel about Scotland itself.
"I would like to improve results at international level, at Under-21s - where they have been doing well - at Under-17 level, at Victory Shield level.
"I want to get a real sense of achievement at those younger age groups as well as at full international level, to try and raise the profile and getting everyone positive again.''