Ronald Koeman made his first signing as Valencia manager with teenage Argentine midfielder Ever Banega completing his switch from Boca Juniors on Saturday.

The 19-year-old Banega signed a deal until the remainder of the current season and five more years thereafter, the club's website reported.

Boca claimed the fee is close to 17.6 million euros (26 million USD) but Valencia have not yet confirmed the figure.

Koeman caused a stir when he informed veteran trio David Albelda, 30, Miguel Angel Angulo, 30, and goalkeeper Santiago Canizares, 37, that they were surplus to requirements as he gives the team a facelift.

Valencia have been in freefall for months crashing out of the UEFA Champions League at the group stage and slumping to seventh in the table.