Real Madrid Castilla's promotion hopes were dented when they went down to a 3-2 defeat at high-flying Real Union de Irun on Sunday afternoon.
Zinedine Zidane's men twice came from behind to level but Jorge Galan's 77th-minute penalty was enough for the hosts, while Alvaro saw red late on after picking up his second booking.
Castilla, who were without Martin Odegaard for the match, sit sixth in Segunda Division B, four points off the play-offs with four games to play this season.
Alan gave the hosts the lead inside three minutes but an own goal from Iosu Esnaola Atxega had things level before Juan Dominguez restored Real Union's lead going into the break.
Castilla hit back again through Aguza ten minutes after the restart but Galan won it from the penalty spot with 13 minutes to go with his second goal of the game.
Izou's side are back in action next weekend when they host Sestao River at Valdebebas.