Yugoslavian Bosco signed for Boro in February 1979 for a fee of £110,000 from Zeljeznicar.
Bosco's balding and slightly overweight appearance was deceptive as he proved to be an excellent finisher who was full of invention. He was spotted by Boro when playing for the Yugoslavian national team and impressed then manager John Neal on a two-week trial.
The signing of the big Yugoslav saw Boro's first move into the foreign transfer market. Bosco's first team debut came as a sub and his first impression was not a good one - he tripped as he ran out onto the pitch.
His first goal for the club came in a 3-0 victory over Derby but his first season was a frustrating one as he struggled to adapt to English football.
However, the next season, the 1980/81 campaign, his fortunes transformed as he found his scoring touch, hitting the only goal in a 1-0 win against Sunderland at Roker Park.
Bosco's strong running and tricky ball skills were a delight to watch inn an attack-minded team that included the likes of Craig Johnston, David Hodgson and David Armstrong.
His finest moment came in the penultimate game of the season as he scored two goals against Bobby Robson's Ipswich side to deny them the championship and put him top of Boro top scorers chart.
After briefly attracting the interest of Chelsea, and also turning out for French side Metz, Jankovic retired and pursue a career as a lawyer back home in Yugoslavia.
Jankovic was later forced to abandon his practice and his property in the war-torn Bosnian capital, Sarajevo, and his death was reported in November 1993, aged just 42.