Ex-England striker Alan Smith believes Chelsea target Diego Costa is one of the best in Europe at the moment. The former Gunner thinks Jose Mourinho’s men will struggle to contain the Spanish striker when the teams meet in the semi-final of the Champions League. Atletico defeated Barcelona this week without Costa to book their place in the last four – the first time they have been in the semi-finals of Europe’s premier tournament in 40 years. The La Liga side have taken Europe and the Spanish league by storm this season, as they chase a fairytale ending to the campaign. Meanwhile, Chelsea staged a dramatic comeback against Paris Saint Germain to reach the last four – with the winners of the Atletico-Chelsea semi-final set to play the might of either Bayern Munich or Real Madrid in the final. And while Smith feels Chelsea will be happy to have avoided the European giants they know Atletico will be no easy task, especially if Costa plays. In Costa they have one of the best strikers in Europe – who Chelsea are after – so it won’t be easy, he told Sky Sports. “It will be a very tactical battle and it will be fascinating to see who comes out on top.” http://bit.ly/SkySportsPass Read more Chelsea transfer news.