Lionel Messi has spoken glowingly about Gerardo Martino following the emergence of his fellow Argentinian as the favourite to succeed Tito Vilanova as the manager at Camp Nou.Barcelona's sporting director, Andoni Zubizarreta, is in Buenos Aires for talks with Martino, who led Newell's Old Boys to the Argentinian Clausura title last season but recently severed ties with the club.Messi would welcome Martino's appointment. He told Diario Ole: "I like Tata Martino. He is a great coach and he showed that in the Clausura with what he did for the team, the way it ended and how he did it. He gets his teams playing well and we all respect him."Barcelona announced on Friday that the 44-year-old Vilanova was stepping down as he continues his battle with cancer. Martino, who also coached Paraguay, has been heavily tipped to beat other candidates such as André Villas-Boas, Michael Laudrup, Marcelo Bielsa, Luis Enrique and Rubi.Feyenoord's Ronald Koeman has ruled himself out. The former Barça and Holland defender said: "That is absolutely not on the cards for me. I do not know who it should be. It's not something that affects me now. I'm more worried about the disease Vilanova has."