Rev Morrison was set to become moderator of the Church of Scotland this year but had to pull out for health reasons.
He will take up the year-long post in 2015 instead.
Speaking about the appointment, he said: "I am thankful that a very good recovery, following surgery, has made it possible for me to accept the nomination.
"My wife and I are deeply appreciative of the support and prayers of so many across the Church during this recent difficult period. In dependence on God's grace, I look forward to the opportunities and challenges of the year ahead.
"On various fronts these are difficult days for our Church, as they are for many other denominations.
"We may at times find ourselves perplexed and saddened, but as people of Christian faith there is no real place for discouragement.
"The Church exists, not for itself, but as God's agent for the extending of his kingdom's just and gracious rule in the world.
"The mission of our Lord continues, and it is our privilege and responsibility to join him in this. In that connection, good news stories are plentiful of faithful and imaginative work going on in congregations and parishes throughout Scotland.
"Despite all the problems we face, God's Spirit is evidently at work among us. The challenge before us is to resist distraction, allowing the commission given to us by Jesus himself, to 'go and make disciples', to remain firmly at the top of our agenda.
Rev Morrison was ordained in 1979 and has been the minister of Orwell and Portmoak Parish Church since 2011.
He has also served as chaplain to Queen Elizabeth II.