Chelsea could make a 'balanced offer' for Sevilla full-back Daniel Alves, according to boss Jose Mourinho. Brazil international Alves is considered one of the top right-backs in Europe, with Mourinho having problems in that position last season when he played midfielders such as Lassana Diarra and Geremi there at times. 'The only thing I know is that we want to make our squad even better,' said Mourinho. 'Right-back is a position we feel we can improve but to improve is not easy, you have to go for a good player and Alves is a good player. 'What's the offer? To be fair I don't know. What Sevilla demand I know even less. I think in the same line as Chelsea have done things in the past, we will make an offer, a balanced offer and not a stupid offer. 'If they accept we will try to get the player, if they don't accept then they don't accept.' While Alves could arrive from La Liga, reports in Spain have tipped Arjen Robben to go in the other direction to Real Madrid. 'His situation has a lot of speculation behind it and also some truth,' said Mourinho. 'We have to wait a bit more to see. Until August 31 anything is possible in terms of people to come and people to go.' Meanwhile, Chelsea have confirmed the arrival of Alex from PSV Eindhoven on a three-year contract. The Brazil defender told Chelsea TV: 'I hope to adapt myself very quickly because (Ricardo) Carvalho and Mourinho will help me with the language barrier, and I hope I can start straight away and won't have any problem to be on the team.'