ARLINGTON, Texas, July 6 : Spain named an unchanged side for Monday's World Cup round of 16 match against Portugal, while Roberto Martinez made one change by bringing in Joao Felix for Rafael Leao in attack.• Luis de la Fuente keeps faith with the Spain team who beat Austria in the round of 32.• Pedro Porro remains at right back, with Dani Olmo in the playmaker role.• Joao Felix starts alongside Cristiano Ronaldo and Pedro Neto, with Leao on the bench. • Ronaldo captains Portugal after saying he will retire from international duty after the tournament.Lineups:Portugal: Diogo Costa; Joao Cancelo, Ruben Dias, Renato Veiga, Nuno Mendes; Vitinha, Joao Neves, Bruno Fernandes; Pedro Neto, Joao Felix, Cristiano Ronaldo.Spain: Unai Simon; Pedro Porro, Pau Cubarsi, Aymeric Laporte, Marc Cucurella;