As well as praising the Catalans' signing of the Brazilian from Santos, the trainer advised Carlo Ancelotti to keep a low key profile at Real Madrid
The Brazilian, who will wear the No.11 shirt at Camp Nou this season, joined in a £49 million deal from Santos ahead of June's Confederations Cup.
And the Russia boss believes the duo will link up together to effect.
"Neymar is an extraordinary player, with unique quality," he told Antena 3. "He has speed, technical quality, shoots with both feet and knows how to always be in the best position [on the pitch].
"I think it will be very difficult to beat Messi and Neymar together, because they have, at all times, the ability to score goals. This is important if you want to win trophies in every competition."
Capello also gave his advice to new Santiago Bernabeu incumbent and fellow Italian Carlo Ancelotti, telling him to try to maintain a low profile and let his team do the talking on the pitch.
"When you go to Madrid, you need to be aware that the club comes before the players, the coach, before everything," the ex-Juventus and England boss added.
"You shouldn't try to be the most important person at Real Madrid. Ancelotti's very smart. He knows how to coach a team. He's a quiet man and he is experienced - he has excellent qualities for leading Real Madrid."
The veteran trainer is also glad that Madrid made mega-money moves for Isco and Asier Illarramendi this summer and believes La Liga has the top prospects in the game in 2013.
"The most promising youngsters in football right now are in Spain, which is why Real Madrid have signed them," Capello continued. "They have experience, talent and they know the style needed to play in Spain."