Boro were one of a host of clubs who chased David Mills' signature when the Thornaby teenager left school. Fortunately, the England youth international decided to join his local club, with Manchester United among the disappointed suitors.
After making his debut as a substitute in the 1968/9 season, he had to wait until 1971 to gain a regular place in the team. But it was as an essential member of Jack Charlton's record-breaking 1973-74 Division Two championship side that Mills really made his name.
He scored 11 goals in 40 games, including the goal that won promotion in a 1-0 win at Luton in March.
Mills also made the breakthrough into the England U-23 squad, winning six caps and scoring three goals. His best season in terms of goals came in 1976-77 when he notched 18 times in 41 league and nine cup appearances.
His form again caught the eye of managers throughout the country and in 1979 Ron Atkinson paid a reported fee of £500,000 for his services and made him Britain's first half-million-pound footballer. But injuries, loss of form and a switch to midfield all conspired to make the switch to The Hawthorns an ill-fated one.
After just six goals in 59 games, he was on his way to Newcastle and then Sheffield Wednesday before his career turned full circle and he re-joined Boro just five years after leaving.
During that time he had scored just 18 goals in 108 league games, having smashed 49 in 167 appearances in a similar period before leaving Teesside.
Back at Boro he soon found his shooting boots again and his 14 goals were crucial in keeping Willie Maddren's side in Division Two. But he didn't play at all the following season after suffering another Achilles injury and a broken arm, and this time Boro were relegated.
After leaving Boro, Mills had a short spell with neighbours Darlington. He later had two spells working for Boro as a scout.