Nadal survives a scare in openerLONDON — Andy Murray's hopes of winning the ATP World Tour Finals were dealt a double blow when he lost his opening group match to Spain's David Ferrer and then warned he could have to withdraw from the tournament with a groin injury. The 24-year-old Scot produced an error-strewn display in a 6-4 7-5 defeat, his first to Ferrer on any surface other than the Spaniard's preferred clay, slumping to defeat in their opening Group A clash in exactly two hours at the O2. Murray often looked leaden-footed and lacked any spark despite leading in both sets. The world No. 3 needed treatment at the end of the first set and although he was able to carry on without calling for the physio again, he could find no way through the formidable defenses of the 29-year-old from Valencia. “Yeah, I mean, I had a problem with my groin. I have to see how it goes for tomorrow,” Murray, who arrived in great form after a recent 17-match winning streak that included three consecutive titles in Asia, told reporters. “I'll decide tomorrow whether or not I keep playing. If it wasn't slams or this event, I wouldn't have played.” Ferrer, who was runner-up at the season-ender in 2007, is exactly the kind of player Murray would have least liked to have faced given his physical condition. One of the game's most durable players, Ferrer scampered all over the court to frustrate Murray's attempts to take charge of the contest. The Scot made 44 unforced errors as he attempted to break down Ferrer. He achieved early breaks in both sets but on each occasion he tamely surrendered his own serve immediately with some elementary mistakes. Ferrer saved a break point at 4-4 in the first set and then sealed the opener in the following game when Murray hooked tired-looking forehand wide of the sideline. Murray tried to fire himself up at the start of the second set despite the muted atmosphere in the less than full 17,500-capacity arena, and briefly appeared to have got back on track when he broke to lead 2-0. However, it proved to be a false dawn as the errors returned and Ferrer began to dictate the points with his forehand in particular testing Murray's suspect groin. Ferrer broke back and then failed to convert two points for a 4-2 lead as Murray hung on. Murray then broke to lead 4-3 when Ferrer missed a forehand but again he failed to build on it, double-faulting on game point to allow the Spaniard to level at 4-4. At 5-6, Ferrer reached match point with a nervy forehand volley which clipped the line and he converted at the first attempt, punishing his opponent for an ill-advised drop shot. On Sunday, an ailing Nadal toiled for nearly three hours before beating Mardy Fish 6-2, 3-6, 7-6 (3), while Roger Federer also needed three sets to win his opening match against Jo-Wilfried Tsonga. Nadal and Federer face each other for the 26th time in their careers Tuesday, although it will be the first time they have met in a round-robin scenario. In a tense evening match at London's O2 Arena, Fish recovered from a nervous opening set on his debut at the tournament and saved two match points at 5-4 in the third set. Despite struggling with illness, Nadal was able to clinch it in the tiebreaker. “I felt very bad from the stomach since the beginning of the third (set),” Nadal said.