MADRID, July 28 (Reuters) - Real Madrid's new signings are giving European and Spanish champions Barcelona cause for concern as they prepare for the start of the new Primera Liga season.'We are conscious of our own strengths but also of the difficulties we face with the new management now in place at Real Madrid,' Barca sports director Txiki Begiristain told the club's Web site. Real's new president Ramon Calderon has installed former Juventus boss Fabio Capello as coach and this week completed the signings of Italy's Fabio Cannavaro and Brazil midfielder Emerson. Dutch striker Ruud van Nistelrooy is set to be presented as their third new face later on Friday, while further signings are expected. 'Step by step Real are putting together a team, although luckily we have more stability and can start working together now as our squad is complete,' Begiristain said. Barcelona have added Icelandic forward Eidur Gudjohnsen and Juve defenders Lilian Thuram and Gianluca Zambrotta to their squad, who have last season won the Champions League and their second successive Spanish title. 'Everyone knows we struggled to win the two titles last season and we have to remember that. If we can get our team playing the same way again I am sure we will be able to be proud of the side once more,' said Begiristain. 'Perhaps we will be able to win a title or two but we won't set a target of how many because it is not fair on the players.'