After their bus was caught in traffic on the way to the ground, Aitor Karanka’s side found themselves 2-0 inside 15 minutes and weren’t able to recover in front of 40,000 travelling Teessiders.
Goals from Cameron Jerome and Nathan Redmond all but ended the match as a contest.
It brought a captivating season to an underwhelming end and, despite the result, there were still plenty of fond memories from that 2014/15 campaign.
None of the players who played for Boro at Wembley remain at the club, though most of them are still playing after moving on.
We’ve taken a closer look at what has happened to the starting XI, subs and manager since the play-off final defeat in 2015.
1. GK: Dimi Konstantopoulos
Now 42, the Greek shot stopper signed for Northern League club Thornaby FC last year. Konstantopulos has ambitions to go into coaching.
Photo: Nigel Roddis
2. RB: Dean Whitehead
After ending his playing career, the former midfielder, 39, has gone into coaching and was assistant manager at Shrewsbury until November 2020.
Photo: Ker Robertson
3. CB: Daniel Ayala
The towering centre-back left Boro last summer but has made just 10 league appearances for Blackburn due to multiple injury setbacks.
Photo: Jamie McDonald
4. CB: Ben Gibson
Following a frustrating two years at Burnley, the Boro-born defender has got his career back on track after helping Norwich win the Championship title.
Photo: BEN STANSALL