The drop in form which has resulted in Andy Murray falling to eighth place in the men's ATP Tour world rankings will not impact on his top-end seeding at Wimbledon, according to tournament officials.

Philip Brook, the chairman of the All England Lawn Tennis Club, has confirmed the reigning Wimbledon champion's strong two-year grass court record will keep him among the top seeds in the competition. Players such as former champions Roger Federer and Novak Djokovic can also expect to benefit from Wimbledon's seeding system.

Officials also defended an increase in prize money for players defeated in the first round, with the total having been raised by nearly 15% to £27,000. Total prize money for Wimbledon has risen by 10.8% from last year to £25m, with the winners of the men's singles and women's singles each taking £1.76m. Last year's prize was £1.6m. The purse for runners-up and semi-finalists has also risen by 10% and for quarter-finalists by 10.2%.

"We have a surfaced-based seeding system here at Wimbledon," said Brook, when asked about Murray's form. "So we take the ranking points of each player and add to that the ranking points they hypothetically received last year on grass, and we add 75% of the best-performing tournament in the previous year.

"To put it into context for Andy Murray, as winner of Queen's last year and winner here last year, and a finalist here in 2012, there will be a significant impact on him. There will also be quite a significant impact on Federer and Djokovic; there will be some adjustment."

Richard Lewis, the AELTC chief executive, said that any Wimbledon qualifier ranks among the sport's world elite and merits increased reward. He dismissed the notion that players would be content simply to take the increased pay cheques for losing in the first round rather than battling to progress.

"The players have worked hard to get there, either they have have got into the championships through their ranking, so that's 12 months of play before. Or there are some wild cards," he said. "So to portray it as £27,000 for turning up and doing nothing . . . I don't think that's valid."

The finishing touches are being put to the planning application to build a roof on No.1 Court. With the application due to be submitted later this year, the aim is to complete the work in time for the 2019 tournament. The alterations will add 900 extra seats - taking the capacity to 12,400.

Wimbledon will be played on 17 courts this year, with renovations to courts 14 and 15 are completed. A host of players complained of injuries because of slippery courts last year but Lewis was adamant that there is no need to make alterations.

"There was an anecdotal problem over a couple of days. Only one or two players took issue with it. We don't feel there are any issues to address on that," he added.