World No 1 tennis player Novak Djokovic says seeing new faces break through to the second week at Wimbledon is positive for the sport.

A total of seven players who will contest the pre-quarterfinals on Monday are unseeded.

“It is a surprise, there’s no question about it. It’s a strange feeling not to have (Roger) Federer or (Rafael) Nadal at the second week of a major. There are some players who have been playing great tennis. I think it’s interesting also to see new faces for the crowd and the tennis world in general,” the top seed was quoted as saying by atpworldtour.com on Saturday.

The Serb, who has not dropped a set in his first three matches, faces German 13th seed Tommy Haas in the fourth round.

“Tommy is full of confidence on the court. You wouldn’t expect him to play quarterfinals of French Open with his game because clay is not his surface, but he did.

“He’s proven everybody wrong because he’s so fit and he moves around the court really well, is very solid from both sides, on the baseline, has a great serve and variety in his game which is perfect for grass,” said Djokovic.

On his own form the 26-year-old said: “Every opponent I’m going to face is going to be more difficult. I’m striking the ball really well and have great balance on the court.”

Baker retires

Scotland’s Jamie Baker has announced his retirement from professional tennis at the age of 26. Baker, who lost in the Wimbledon qualifiers, has struggled with injury and illness throughout his career, including an auto-immune disease in 2008 that left him in intensive care for three days.

“I was told at one point for about a 24-hour period literally not to hold my breath for too long, let alone move because if a bleed started in my head, there’s nothing they could do,” the Briton told BBC on Saturday.

“Amazingly from that, by far the biggest achievement in my career has actually been from that point where I was really rising up the rankings very quickly. I had won consecutive tournaments, I had qualified for the Australian Open - from that setback I actually came back about four years later and reached my highest ranking again,” said Baker, whose best ranking in singles has been No.186.

“It’s probably hard to measure how much that process took out of me. It was incredible what I went through and the hardest time was actually afterwards.”