on 1st July 2023 Norwich completed the signing of 22 year old Spanish winger Borja Sainz on a free transfer. He was available due to a clause in his contract which was activated when Turkish side Giresunspor were relegated from the Turkish top flight. He had played 34 appearances last season for Giresunspor, scoring 10 goals.

Prior to his time in Turkey, Sainz’s previous clubs include AD Lagun Artea, Athletic Bilbao and Deportivo Alavés, where he featured 40 times in La Liga, before a loan spell with La Liga SmartBank (second tier) side Real Zaragoza. He has been capped by Spain at Under-19 youth international level.

Head coach David Wagner said: “We’re very pleased to welcome Borja to our squad. He’s a young player, but already has good minutes in the top levels in both Turkey and Spain. We’re really pleased to have completed his signing so that he can start work with us at this stage of pre-season and learn his role in our team. When I spoke with him you could really feel his desire to come in and make an impact. He is hungry to prove himself and exactly the kind of player we want to have in our group.”

After experiencing injiury in pre-season, Sainz finally made his Norwich debut as a 63rd minute substitute in the League Cup clash at Fulham on 27th September 2023. He scored Norwich's consolation goal on the 75th minute in a 2-1 defeat. His league debut came as substitute against Birmingham three days later. Sainz made a total of 39 appearances, scoring eight goals, in 2023/24 as Norwich finished sixth reaching the Championship play-offs, before losing 4-0 to Leeds.

Sainz was named as Championship Player of the Month for September 2024 after scoring four goals including a hat-trick against Derby. His blistering form at the start of the 2024/25 season in which he scored 11 goals in the first 15 games saw him linked by Spanish outlet Mundo Deportivo with a return to Spain with Athletic Madrid, Villareal and Athletic Bilbao all reported to be interested as well as Galatasary and several Premier League sides.