Real Madrid new signing Theo Hernandez aims at stopping Lionel Messi when they clash in the Copa Dey Rey finals.The left full-back insists that stopping the Argentine forward is his aim at the moment, the 19-year-old was linked with Barcelona, Real Madrid beat the Camp Nou giant to his signature but yet to be announced by the Bernabeu chiefs.The full-back has impressed during a season-long loan from Atletico Madrid as he his performance has led to Real Madrid signing him from Atletico Madrid been his parent club.At the moment, he is determined to concentrate on Saturday's encounter at Vicente Calderon, as his side, Deportivo Alaves look to shock Luis Enrique's side for the second time this season."We're very happy and we're going to try to face the final with all the excitement in the world," he told Mundo Deportivo."I've always been in my own space. I'm relaxed and everything is totally normal. "I don't talk about [the Madrid], I talk about the final. I've just done my job, as usual. If there are big clubs, it's a reward."For now, I'm going to continue playing as I have been. I'll continue to grow and we'll see what happens in future."I wanted to play this final because it's a dream for me. Of Course, we can win. We won there, at Camp Nou, in La Liga."Initially, I didn't think I'd be able to be where we are with Alaves. With the work and the effort of the whole team, we've reached a big final."I'm always excited about beating Barca. They're a great team. It's very difficult to stop Messi but we're going to do everything possible to try."Alaves won 2-1 at Camp Nou in the league in September, although Barca did triumph 6-0 in the reverse fixture. Theo wants to win the final for Alaves fans for him to bid them a memorable goodbye as he seeks new adventure in Real Madrid next season.