Ryan Grant last night stepped off the emotional rollercoaster he has been riding for most of his career and began the journey of his dreams.

The former soldier, whose career once stalled so badly that he considered giving up rugby altogether, has been called up to the British and Irish Lions as injury cover for Wales prop Gethin Jenkins; overdue recognition of the quality of a player who had a strong claim to be in the squad in the first place.

In fact, the 27-year-old suffered the pain of rejection twice: when he was overlooked for the original party named last month by coach Warren Gatland, and when England's Alex Corbisiero was chosen ahead of him to replace the injured Cian Healy just a few days ago. However, the hurt was obliterated when he was told that the Lions wanted him after all. Grant, who only began to fulfil his potential after moving from Edinburgh to Glasgow two seasons ago, had little time to collect his thoughts before setting off from Scotland's team base in South Africa for the long journey to Brisbane.

Grant only found out about his call-up at 11am yesterday morning when he was beckoned to Scotland coach Scott Johnson's room at the team hotel near Durban, where Scotland will play Samoa in the opening match of the Castle Lager Test Series today. His pace in the side will be taken by Alasdair Dickinson, with Moray Low being added to the bench.

"I went up to Johnno's room, he said he wanted to talk to me about where my head was after the last couple of days," said a smiling Grant before racing to Durban airport to catch a connecting flight to Johannesburg. "Then he gave me the good news. After that it was 'congratulations, pack your bags'."

Grant's omission was one of the most controversial decisions made by Gatland, who saw fit to include just three Scots – Stuart Hogg, Richie Gray and Sean Maitland – in his original squad, despite the fact that others had thrust themselves into contention with their performances in the Six Nations.

"I was disappointed when the initial selection came out," Grant admitted. "But every cloud . . . I got to come out here with my mates. It has been great, I love Durban and have been having a great time here. When the news came about Cian Healy, there was an element of excitement that I might go, but at the same time I was content here. So to get this news this morning, I am over the moon."

Of the selecion of Corbisiero ahead of him, Grant said: "It was disappointing but at the same time so close to a Test match, I had a lot to focus on. I have some of my best friends out here – who better to talk to than your teammates and your mates when you are feeling a bit down. I was a little bit gutted, but quick to snap out of it."

Scotland captain Kelly Brown was quick to sing Grant's praises and backed him to do well in Australia. "He has had an outstanding season," said Brown. "Over the year he has been strong at the set-piece, he works hard around the pitch and is often in the top two or three tacklers in the team. As a loosehead prop that is a very impressive stat. He is a very good carrier. He is someone who, out there on the hard grounds, could be outstanding."

Grant, who was born in Kirkcaldy but raised in the Far East, left the Royal Corps of Signals to pursue his dream of a rugby career. He spent time at the now-defunct Border Reivers before being taken on by Edinburgh, but he had few opportunities at the capital club, making just two starts in three seasons and only rarely figuring as a substitute.

However, he thrived after moving to Glasgow. His opening came when first-choice loosehead Jon Welsh - who is expected to take Grant's place in the Scotland party - suffered an injury, and he has never looked back. He won his first cap in the 9-6 win over Australia on last year's tour, and has now made a total of 10 appearances for his country.

Grant's selection continues a great tradition of Scottish looseheads being chosen for the Lions. Hugh McLeod, Ian McLauchlan, David Sole and Tom Smith were all unfancied as Test contenders when they were first called into the British Isles squad, but all became first-choice Test players.

Scott Johnson, the Scotland coach, said: "We are delighted for him and he goes out with heaps of best wishes because it is a wonderful achievement. It is a lifetime achievement and his form has warranted it. He is a wonderfully gifted rugby player and they may be pleasantly surprised at what they have got, and that is a nice thing for Scotland."

Al Kellock, Grant's club captain at Glasgow, also backed the prop to thrive with the Lions "I would not bet against him to go over there and have an exceptional tour," said Kellock. "When you get him into your environment you see what he has to offer. He will get an opportunity to play over there and grasp it.