Carlos Gurpegui has been named Bilbao Athletic coach for the new season.
Gurpegui has been promoted from the C team.
"It's a great new challenge, and I'm looking forward to the opportunity the club is giving me," Gurpegui said upon being announced as the new B team head coach.
"I have the advantage of knowing practically the whole squad from the year and a half I've been at Basconia, and I hope to have a great season. Every coach at Lezama has a very big responsibility towards the Club and the players, even more so with the philosophy we have.
"We're all very important, our main objective here is to supply the first team with capable players, making sure they get there with the highest level both in sporting and intellectual terms. We all have to be clear about that."
Director of football Mikel González also said: "We believe this to be the best decision for the interests of the Club.
"Carlos Gurpegui has been working at Lezama in different areas for several years now, first working individually with the players and then as a coach. He knows the squad and Athletic perfectly, and has a magnificent relationship with the first-team coach.
"He's the in-house coach whose style is most similar to Ernesto Valverde's and that has played an important role in the decision."
Meanwhile, U18 coach Bittor Llopis will be the CD Basconia manager next season, replacing Gurpegui.