Nanabanyin started his early football career at the Methodist school in Sekondi. The lanky Aggrey-Fynn, as thin as the thread, showed emense talent and dexterity at that early age. His dribbling ability and the ball sense displayed at that early age, made him a shinning star in the making.
When Aggrey-Fynn returned to Cape Coast to enrol at the Ghana National College to commence his secondary school education, his talent and capabilities as a footballer caught the eye of the sports master who immediately selected him for the school team.
The two Cape Coast teams,Venomous Vipers and Mysterious Dwarfs, started chasing for him. Dwarfs were the luckier of the two and got him into their fold.Whatever happened after that belongs to history as he had to leave cape coast on the completion of his secondary education to take up appointment at the Audit Department in Takoradi and subsequently joined the Sekondi Hasaacas FC.
Aggrey-Fynn started growing in stature as a footballer. He was still lanky and thin and started displaying football artistry as a schemer and scorer at the same time. He had an immaculate sense of judgement with tailor-measured passes from the middle.
He was tireless and covered a lot of grounds in the game. A new football star had emerged in Sekondi and became a thorn in the flesh of defenders of all teams swhich went to Gyandu Park.Gyandu became the waterloo of many clubs which played against Hasaacas. Kumasi Asante Kotoko suffered most when Aggrey-Fynn turned many certain victories of Kotoko into defeats.
On one occasion, Kotoko led Hasaacas 3-0 at half time and missed a penalty at the commencement of the second half.
But when the master,as Aggrey-Fynn was called in those days, sparked off in the second half with his masterly dribbling and scheming techniques,the miracle of Gyandu manifested and Aggrey-Fynn's Hasaacas mesmerised, outplayed and outscored Kumasi Asante Kotoko with a 4-3 victory.
Aggrey-Fynn was a doubtful starter for this match, as his left wrist had been cast in a Plaster of Paris as a result of injury received in a previous match. He became a "problem player" for Kotoko in subsequent matches as he masterminded and executed with precision several tactical movements which resulted in defeat of Kotoko and that of other teams.
Naabanyin became a founding member of the Black Stars in 1958. He subsequently transferred to Accra and joined Accra Hearts of Oak. Again, "Kofi Gyata", as we called him, raised Accra Hearts of Oak to the highest pedigree at that time with many brilliant goals scored in the league and exhibited a high level of leadership qualities.
It was no surprise that when Ghana Real Republicans football club was established as a model club for Ghana, Aggrey-Fynn was elected as the captain to lead the Republicans and he was subsequently appointed the captain of the Black Stars.
The late Mr. Ohene Djan described Aggrey-Fynn as football's "Gentleman Strategist" whilst the late Mr. H.P. Nyemitei labelled him the “master tactician”. As captain of the Black Stars on an European tour of 1961, Aggrey-Fynn excelled as a leader and remained the supreme of the Black Stars until they conquered Africa to become the winners of the 1963 Cup of Nations hosted by Ghan.
He led the Black Stars to qualify for the first time to play in the Tokyo Olympics of 1964. Aggrey-Fynn, known also in his days as “professor”,was adored, admired and worshiped in football circles as a master of all the surveyed.
No wonder, when he scored the vital equaliser on the 89th minute for the Black Stars against Nigeria, in a keenly contested Cup of Nations qualifier at the then Accra Sports Stadium (now renamed after the great sports administrator Mr Ohene Djan),the big crowd at the stadium echoed the name "Osagyefo" as another accolade to Aggrey-Fynn.Osagyefo was at that time the official title of the state president.
This meant that since there was only one officially known Osagyefo in the country, it would be improper for Aggrey-Fynn to be called Osagyefo. Aggrey-Fynn had to make a subsequent statement to the press making it categorically clear that his name was Aggrey-Fynn and not Osagyefo as people were calling him.
This was the height of his popularity as a footballer. The soft spoken football star had become a national hero. His playing career was cut short after he was involved in a car accident which incidentally happened at Kwesi Mintsim in the Sekondi-Takoradi municipality.The late Mr Lawton Ackah-Yensu and myself were with Aggrey who was driving at the time.
He had a serious ear injury and was later sent by the late Mr Ohene Djan to the United Kingdom for treatment . Aggrey-Fynn became a successful football coach culminating in my selecting him as my assistant, when I was appointed the national coach in 1968.
In 1970, when Asante Kotoko were made to join the national squad for their preparations in the Africa Club Championship, I assigned Aggrey-Fynn to take full charge of Kotoko with my full technical support base. The result belongs to history. Kotoko became the first club from Ghana and West Africa to win the trophy after defeating Engelbert of Congo.
Aggrey-Fynn became the national coach of Ghana in 1974 after I had resigned to take up appointment in Ivory Coast in 1973. Whilst I was the firebrand type in maintaining discipline in the team, Aggrey-Fynn was calm and persuasive in his dealings with our boys.