The wage bill at Premier League football clubs surged to almost £3bn for the first time last season, according to a report.
Initial figures covering the 2017/18 season from the sports business group at Deloitte showed the 20 sides spent £2.9bn on salaries - a 15% increase.
It said that combined revenues hit another record sum - £4.8bn - to help pay wage demands though the revenue sum was only 4% up on the previous season, meaning overall profitability took a hit.
The report calculated operating profits of £900m, down from £1bn a year earlier.
Arsenal, Liverpool and Tottenham Hotspur contributed more than 75% of the profits, it suggested, though there was an increase in the number of clubs that were loss-making despite securing record sums from the current TV rights packages.
Overall revenue was also bolstered, Deloitte said, by Premier League clubs enjoying a stronger performance in the Champions League last year with five teams reaching the Round of 16 or beyond.
Alongside the increase in UEFA distributions, matchday and commercial revenue both grew by 8% and 12% respectively.
It meant, the study said, that almost 60% of combined revenue in the league was now being spent on wages - up from 55% in 2016/17.
Deloitte sports group director, Tim Bridge, said: "The increased wage expenditure was expected given the busy transfer market in the 2017/18 season, with two record transfer windows driving estimated Premier League gross spend of £1.9bn.
"However, with the total value of Premier League broadcast rights expected to only marginally increase in the 2019/20-2021/22 broadcast rights cycle, increases in wage and transfer expenditure may be expected to slow in the medium term, as already signalled by the reduced estimated £1.4bn gross transfer spend in the current season.
"With the emphasis now on clubs to generate revenue growth from sources other than central broadcast distributions, it may be that we see the levels of pre-tax profit diminish over the next few years," he concluded.