The forward signed from RCD Espanyol where, having progressed through the Spanish side’s academy set-up since a young age, the 18-year-old’s contract was due to expire in the summer.
Bagging 14 goals across 21 appearances for the Periquitos’ under-19s side last season, Joseph’s exploits attracted the attention of several European giants.
Liverpool and Manchester City were both said to be interested, while Barcelona reportedly made overtures toward the youngster last summer, but the Spanish side did not meet the asking price set by Espanyol.
This week, Joseph arrived in LS11 in order to put the finishing touches on a deal that Whites director of football Victor Orta has been pursuing for several months.
Initially, the teenager will join up with Mark Jackson’s Under-23s, who are looking to climb out of the relegation zone after slipping to 13th place in the Premier League 2 standings.
The young Whites are in desperate need of some good form as they attempt to shake off a winless run of PL2 games which stretches back to September.
After committing his future to Elland Road on Tuesday, Joseph took to social media to express his determination to make an impact.
“Today I lived one of the most exciting days of my life and I only have words of gratitude for all Leeds United for the welcome they gave me, I felt at home,” Joseph wrote on Instagram.
“Today a new challenge begins, surrounded by my family that has always been there for me.
“I will give everything to defend these MOT colours.
“Thank you all! Let’s gooo.”

1. Man United target Neves
Marseille’s Boubacar Kamara and Wolves’ Ruben Neves are two of a number of players Manchester United have been looking at in their search for a new midfielder. (Sky Sports) (Photo by Naomi Baker/Getty Images) | Getty Images

2. Digne attracting interest
Everton left-back Lucas Digne has drawn interest from Chelsea, Newcastle and West Ham. (Sky Sports) (Photo by Marc Atkins/Getty Images) | Getty Images

3. Villa lead Coutinho charge
Aston Villa are leading the race to sign Philippe Coutinho on loan this month. (Sport) (Photo by Aitor Alcalde/Getty Images) | Getty Images

4. Spurs keen on Lamptey
Tottenham are ready to challenge Arsenal in the £50 million race for Brighton defender Tariq Lamptey. (Express) (Photo by Chris Brunskill/Getty Images) | Getty Images

5. Toon lead Ramsey race
Newcastle are in pole position to sign Aaron Ramsey from Juventus, but Leeds, Leicester, Crystal Palace, Wolves and Everton are also keen. (90min) (Photo by Catherine Ivill/Getty Images) | Getty Images

6. Ramsey rejects Clarets
Ramsey has also reportedly already rejected an approach from Burnley. (Calciomercato) (Photo by Dean Mouhtaropoulos/Getty Images) | Getty Images


