NEW YORK (AFP) - Nikolay Davydenko faced more skepticism and questions Tuesday after an upset loss at the US Open, a still-unfinished match-fixing probe involving gamblers haunting the Russian fifth seed. Accusations regarding odd betting patterns began after a surprise loss 13 months ago in Poland. Davydenko vigorously denied any claims of impropriety over an anonymous contest that sparked seven million dollars in online wagers. After being worn down over a season where every sub-par performance was viewed with a scornful eye, Davydenko had to defend himself against those who thought he might have tanked his fourth-round loss to 130th-ranked qualifier Gilles Muller of Luxembourg. "It's always tough to say. I can beat everyone and I can lose to everyone," Davydenko said. "He was playiong good. Normally I have a chance to win but I didn't. What can I say? It's not a thing involved in the investigation. "I tried to prepare good. I tried. I wanted to win. But I didn't." Davydenko won his two prior matches against Muller, in 2006 on Estoril clay and last year in the second round of the Australian Open, and had not dropped a set to him until now. The ouster of the 2006 and 2007 US Open semi-finalist came amid British reports that Davydenko might be on the verge of being exonerated in a probe. That thought prompted busy Davydenko to say he might play even more in 2009. "Maybe next year I will start to play more tournaments. This year I was pretty tired. I didn't want to play so much tennis," Davydenko said. A season under suspicion, including a Wimbledon first-round loss to German Benjamin Becker, had made Davydenko weary. "Some months I dropped the tennis," he said. "After losing first round at wimbledon I was so tired, mentally and physically. I didn't want to play and I didn't practice well and I didn't care. "Now I was finishing season, thinking make a good result here and try to prepare for Davis Cup. I tried my best to prepare. I don't know how I feel mentally or how I want to prepare. It was a problem." Davydenko said he likes to play events so that even if he loses he has easy access to practice courts, dumping the sport when not in the environment. "I can practice all day. Maybe I have a chance at more practicing and can make a better result. That's why I play so many tournaments," he said. "When I rest I don't want to play tennis."