Bolton have completed the signing of left-back Marcos Alonso from Real Madrid for an undisclosed fee. The 19-year-old is now the third signing of the summer for Trotters boss Owen Coyle, following the arrivals of Martin Petrov and Robbie Blake. Alonso joins Bolton on a three-year deal, with the highly-rated defender set to compete with Paul Robinson and Jlloyd Samuel for a place in the starting line-up. Real Madrid gave Alonso his debut for the first team in April last season, coming on as a substitute for Gonzalo Higuain in their 2-0 victory over Racing Santander. Coyle was delighted at sealing the deal with Alonso, saying the Spaniard is one to watch out for in the future. "He is an exciting young player who has undoubted quality and he will bring that into our mix. I think that we have a real talent on our hands," Coyle said. "I have said before that when we are investing money in transfers that I want to do it with young, talented players. "He isn't the finished article yet - he's a young player making his way - but you don't get through at Real Madrid without having a bit about you."