Andy Murray will have to wait for the clouds to clear before he is able to make out who will face him in the fourth round at Wimbledon.

While the Scot scarcely had to contend with perspiration during a straight-sets victory over Tommy Robredo yesterday, it was a more malignant source of moisture which obscured the identity of his next opponent – with the match between Russia's No.20 seed Mikhail Youzhny and Serbia's Viktor Troicki delayed due to rain.

Neither have managed to get one over on Murray in their careers but given some big names have already been scribbled out in the early rounds of the competition, both could be forgiven for believing they are quite capable of drawing a line through the Scot on Monday. With that match likely to be on Centre Court they will at least be able to keep dry as they give it a go.

Should the world No.2 continue his impressive progress at the All England Club, though, he will have a better idea of his prospective route to the final, since Adrian Mannarino squeezed past Dustin Brown last night 6-4, 6-2, 7-5 and could block Murray's path at the semi-final stage. Another who could swat at Murray in the last four is Jerzy Janowicz – the 6ft 8in (bean) Pole who overcame 15th seed Nicolas Almagro in straight sets to reach the fourth round of a grand slam for the first time in his career.

His tall frame carries a large reserve of power and his performance comprised 30 aces and a series of thumping volleys which bludgeoned his Spanish opponent into defeat. Yet Janowicz is also a gifted and affable character and he hopes to also leave a lasting impression on the crowd. "I think the fans enjoyed the match, but I don't like to talk too much about myself," said the 24th seed. "But I hope they like me and I hope I have a chance to play one more match on the Centre Court."

He must first tame Jurgen Melzer in the fourth round if he to enter the jaws of Centre Court again, though, and Janowicz showed little intention of dropping focus, or his form.

David Ferrer can vouch for the need to keep your concentration, with the Spaniard almost caught out by compatriot Roberto Bautista Agut yesterday. The pair are competing in the opposite half of the draw to Murray – with Novak Djokovic looming – but spectators were invited to be just as attentive as Ferrer battled away for almost three hours before making off with a 6-3 3-6 7-6 (7/4) 7-5 victory on Court No.1.

It proved to be a somewhat arduous afternoon for Grigor Dimitrov too, albeit one which was not as successful as he fell to Grega Zemlja. Oddly enough, though, it was not Slovakian who represented the greater obstacle – Dimitrov being made to contend with wet weather and one ungainly fall at 30-30 in the opening game.

"It started raining in the warm- up and I thought the chair man [umpire] would say something," he said. "I was kind of waiting for that call. I slipped and hit my hip. I told him I wasn't serving. I would consider myself pretty aggressive and it's tough when the grass is really slippery."