Captain Walter Barrie was playing in a match between British soldiers and members of the Afghan National Army (ANA) when he was shot dead in the insider attack at his base in Helmand province.
The 41-year-old – survived by a son, Callum, 15, pictured, and wife Sonia, was the 14th British serviceman to be killed by Afghan soldiers or police this year. He had been mentoring and advising a brigade of the ANA to take over security in an area of southern Afghanistan.
He had served with the Royal Scots Borderers, 1st Battalion The Royal Regiment of Scotland (1 SCOTS), for 25 years, including tours of Iraq, Bosnia, Kosovo, Northern Ireland and Afghanistan in 2008.
Mrs Barrie last night said: "Captain Walter Barrie was a great man, a doting and amazing father and a fantastic husband. He was much loved and will be missed by many."
The death takes the number of UK service members killed in Afghanistan since operations began to 438.
At least 54 international troops have died in "green-on-blues", where Afghans turn their weapons on their coalition colleagues.
News of the killing came after the Queen led the nation in honouring the fallen, as the country fell silent on Sunday to remember its war dead.
Capt Barrie, of Lanark in South Lanarkshire, was deployed to the Nad-e Ali district of Helmand on August 31. He was a keen skier and a Football Association coach who had a "youthful drive and zest for life".
He was described by his colleagues as a fanatical Rangers fan who always had his family at the forefront of his mind.
Lieutenant Colonel Benjamin Wrench, commanding officer of 1 SCOTS, said: "His role as an adviser to the Afghan army was one he trained for, looked forward to and performed superbly.
"His ability to build relationships and rapport has always made an impact on those who met him. This was down to his enthusiasm for life, for youth and humanity.
"As can be seen from the many tributes, he enriched the lives of everybody he came across. His winning personality and Glaswegian wit will be sorely missed, as will the banter we often had as a result of his fanatical support for Glasgow Rangers.
"It is almost impossible to express the sadness we, as a close battalion, are experiencing at this time.
"I know the impact of his tragic loss will be felt across our regiment, amongst the soldiers, officers and in particular the late entry commissioned officer community. But we remain committed in our role and mission in Afghanistan and we will do so knowing that Walter would expect nothing less of us all."
Captain Bob Stuart added: "Walter was a true friend for more than 20 years who I have grown up with through this period and worked alongside on numerous occasions.
"Walter was a complete professional and dedicated to his profession. He had a natural, exceptionally sharp wit which was enjoyed by all, and he enjoyed nothing more than some banter with the Jocks when the situation allowed. He was a soldiers' officer and respected by everyone who met him."
Major Andy Lumley, officer commanding of D Company, 1 SCOTS, described Capt Barrie as "truly wonderful man".
He added: "I am lucky enough to have counted him as my friend."