LILLE, France - Switzerland's Stan Wawrinka left the ATP World Tour Finals feeling wrecked last weekend but said on Thursday he had fully recovered for the Davis Cup final against France.

Stan Wawrinka of Switzerland gestures towards the coaches and family box of Roger Federer of Switzerland, during their semi-final tennis match at the ATP World Tour Finals at the O2 Arena in London November 15, 2014. [Photo/Agencies]

The world number four wasted four match points in losing a tight semi-final to Roger Federer in London last Saturday when he fumed at his team mate's wife for heckling between serves.

Both players settled the argument and have played down the row with Wawrinka having showed he is back to his best after struggling for form following his Australian Open triumph.

He showed terrific improvement in London and is now mentally rested as well.

"Clearly on Saturday night I was destroyed. It was difficult to accept that loss. I did everything I could to win that match," Wawrinka told a news conference on Thursday after the draw ceremony fort this weekend's Davis Cup final.

"Sunday was also a difficult day. It's always difficult to take. I was hurt."

But a change of scenery and a new objective have helped Wawrinka turn the page.

"When I came here with the physio and everything, everything was different. It was a new week, a new state of mind," he said.

"So mentally it was easy for me to switch, to forget about this big disappointment, start on something positive."

Reflecting on his London week, where he rediscovered his touch, Wawrinka said the overall experience was rewarding.

"I took a lot of positives from that week. I'm feeling great from London, a lot of confidence from there. Playing really good tennis," he said.

"I had five days here to change surface, to play on clay. I did what I could here with some good practice. I'm feeling ready for the weekend."

He will open proceedings in the best-of-five series against French number one Jo-Wilfried Tsonga on Friday.