Calder, who was capped 34 times for Scotland and captained the successful 1989 British & Irish Lions Tour to Australia, said, "I am sorry to hear the news but its understandable as he has found himself under enormous pressure. He has come under sometimes unwarranted criticism and I feel for him. I hope he has come to this decision himself and wish him luck.
"It is very hard to know who might replace him as there is not exactly a queue of people lining up. I very much hope that Andy Robinson (Edinburgh) and Sean Lineen (Glasgow Warriors) might consider the position as they are both doing well with their professional teams.
"I am disappointed for Frank and feel it is not a good day for Scottish Rugby."
Sharing Finlay's sentiment was Fergus Slattery, the former Ireland flanker who toured twice with the Lions, including the victorious 1974 Tour to South Africa. He said, "I am very sad. He was a lovely man and was in a very tough position - not one I would like to be in. Coaching a national side does rely on a certain degree of luck and Scotland have not had a great deal of that recently, and are an average side right now.
Hadden has been there for a few seasons now and not made the kind of progress that either Frank or the Scottish Rugby Union would have liked so its understandable that this has happened, but its still unfortunate."
Gerald Davies, the legendary Welsh and Lions full back who is Tour Manager for this summer's British & Irish Lions Tour to South Africa, added, "This just demonstrates how tough it is at national level for a coach. I didn't know Frank personally but it is such a tough world for coaches nowadays. Unlike a manager, it is always the coach who is in the front line and in the spot light which makes it a very hard place to be."
All three were speaking at an HSBC Lions Legends dinner in aid of the Lions Charitable Trust. HSBC is Principal Partner and shirt sponsor of the British & Irish Lions Tour to South Africa.
Rights free photographs of Calder, Slattery and Davies in Edinburgh are available. Please contact firstname.lastname@example.org