Spanish defender Daniel Ayala initially joined Boro on a 93-day emergency loan from Norwich City in October 2013 and signed on a permanent deal in January 2014.
He scored with a towering header on his debut in the 4-0 win over Doncaster Rovers at the Riverside.
Daniel began his career with Boro's UEFA Cup conquerors Sevilla before Rafa Benitez signed him for Liverpool in 2007.
He made five Premier League appearances for the Anfield club, his debut coming as a substitute against Spurs on August 16 2009.
He impressed with his tackling ability and composure on the ball and after successful loan spells with Hull City and Derby County in 2010/11, he joined the Canaries in August 2011, signing a four-year deal.
Standing 6ft 3ins tall, Dani, who has one Spain Under-21s cap, spent the 2012/13 season on loan with Nottingham Forest.
He joined Boro permanently in the January 2014 transfer window, signing a three-and-a-half year contract for an undisclosed fee.
Dani was voted PFA Championship Fans' Player of the Year for his commanding displays in Boro's 2015/16 promotion-winning season, and was awarded an extended deal in the subsequent summer, which will keep him at the Riverside until 2020.
He found his goalscoring touch in the 2017/18 season when he scored seven in 40 appearances.
That put him in a small, but elite list of Middlesbrough centre-halves who have scored as many in one season. Only Willie Maddren, Tony Mowbray and Mel Nurse have reached that mark.
The 2018/19 campaign ended with Dani just one short of 250 career appearances, 191 of which have been with us.