The German tennis pros around Alexander Zverev have had a disappointing start to the new United Cup and are facing their first defeat.

In the opening duel with the Czech Republic, the 25-year-old Olympic champion lost his first official match on the tour since his foot operation in Sydney on Saturday 4: 6, 2: 6 against the world number 81.

Jiri Lehecka.

Jule Niemeier then lost 2:6, 5:7 to Marie Bouzkova, meaning that the German Tennis Association needs three victories on Sunday to turn the game around.

"Physically, I'm not yet at the level I need to be," said Zverev after the game.

"This is not a question.

I get tired a lot quicker than before.

I'm not as fast as I probably was."

Before the preparatory tournament for the Australian Open (January 16 to 29) and the start of the new season, Zverev had only gained game practice at show appearances after his serious ankle injury at the French Open in June.

In Dubai before Christmas he had succeeded against the former world number one Novak Djokovic from Serbia.

Zverev reported that he had only been pain-free for two or three weeks.

Zverev's match lasts 94 minutes

After a mandatory seven-month break, it has now become apparent that he is still far from top form.

Zverev gave up his serve four times against the 21-year-old Lehecka and had to admit defeat after 94 minutes.

"I knew before the match that he hadn't played for a while, but against a player like him it doesn't mean anything," said the Czech outsider after his success.

If Laura Siegemund doesn't manage to surprise Petra Kvitova on Sunday, the defeat in the country comparison would be fixed.

In addition, Oscar Otte meets Dalibor Svrcina, for the final mixed Julia Lohoff and Fabian Fallert are nominated.

The American selection around US Open semi-finalist Frances Tiafoe, who won 4-1 against the Czech Republic at the start, is the second opponent of the German team on January 2nd and 3rd.

A total of 18 nations are fighting for progress in six groups of the new competition for women and men. The winner will be determined in the final on January 8th.

Aside from Sydney, where the final round will also take place, Brisbane and Perth will be played.

The United Cup is also about world ranking points and a total of 15 million US dollars (14.05 million euros) in prize money and bonuses.