Spain: Manchester United open their Champions League Group D campaign at Villarreal in Spain on Wednesday. They have a dreadful record in Spain, with only one win in 15 visits in the premier European cup competition. But Sir Alex Ferguson's side have received a fillip from the return to form of striker Ruud van Nistelrooy, with five goals already this season. The Dutchman, who has scored 37 times in 41 Champions League games, will be accompanied in attack by Wayne Rooney. Injury problems Club captain Roy Keane has pulled out after suffering a hamstring strain in training, with the Irishman's replacement likely to be Alan Smith, who played in midfield against Manchester City on Saturday. Ferguson, who guided United to Champions League victory in 1999, looked on as their English rivals Liverpool went all the way in last season's competition. But the Scotsman claims to have felt little in the way of jealousy at seeing another Premiership team lift the trophy. United winger Cristiano Ronaldo, who missed Saturday's Manchester derby to attend his father's funeral in Portugal, has returned and been added to the squad. Ferguson said it was an unexpected surprise. "Yes, he has travelled with us, and it was a surprise. We didn't know when he was going to be due back, but we left it to the boy himself. He came to training yesterday and we're very happy about that. He feels fine," he said. Steady progressMeanwhile, Villarreal may not be among the biggest sides in Spain. They have been in the Spanish top flight for just six seasons prior to this one. The town, which is near Valencia, only has a population of 40,000. But they have been punching above their weight - finishing third in La Liga last season, and reaching the UEFA Cup semi-finals and quarter-finals in the last two years. Their progress has been based upon a series of shrewd South American signings, among them Paraguayan striker Diego Forlan - from, ironically, Manchester United - and Argentine midfielder Juan Roman Riquelme. There could be up to six other South American players in the starting line-up, and, appropriately, they are coached by a Chilean, Manuel Pellegrini. They defeated another English side, Everton, in the preliminary round, and will be seeking to worsen United's poor record in Spain when they make their debut in the Champions League proper on Wednesday. Perfect opportunitySomething of a disappointment during his time at Manchester United, Diego Forlan has been transformed into one of Europe's most feared strikers after moving from Old Trafford to El Madrigal last year. Forlan now has the perfect opportunity to demonstrate his true worth against his former club. "We are very happy to be at this stage (of the competition). So we are trying to be calm, and try to approach the game the best way that we can, so we know it's going to be a very difficult game. However, we are hoping to start very well, and trying to win this game, which is very important for us," said Forlan.The contrast between United, one of the world's richest clubs, and modest Villarreal, could hardly be greater. But Villarreal, with a 100 per cent European record against English clubs, will be underestimated at United's peril.