Playing tennis matches late at night does not look very "professional" and the sport needs to look at the issue, says Andy Murray.
The former world number one was still on court at nearly 01:00 BST on Thursday in Glasgow, playing doubles with Joe Salisbury in Great Britain's Davis Cup defeat by the United States.
Earlier this month Carlos Alcaraz and Jannik Sinner played until 2.50am in the US Open's latest ever finish, one of two occasions champion Alcaraz competed beyond 2am in New York.
"It's something that tennis needs to sort of have a bit of a think about," Murray, 35, told a news conference. "I don't think it looks that professional."
While a good-sized and passionate crowd remained at Emirates Arena to watch Murray and Salisbury in their 5-7 6-4 7-5 doubles defeat by Rajeev Ram and Jack Sock that decided the Davis Cup group-stage tie, it was far from the packed arena it had been earlier in the day.
"It would be better if they were earlier I think for everyone involved," said Murray, whose match started at 22:00 BST.
The tie had got under way at 16:00 BST with back-to-back singles rubbers both going to three sets.
"I don't think it's ideal for you guys [media]. I don't think it's ideal for the fans," he added. "That match that we played there, there's probably half of the people in there at the end of the match that were there at the beginning.
"It's a bit of a shame because they missed a great match. It's not probably because they didn't want to stay. If you [have] got children here, you can't stay with them. [If] you [have] got to get a bus or train home, [you] can't do it."
He added that for the ball boys and girls late finishes were "inappropriate" and that while the players were still able to compete to a high level, the knock-on effect the next day was tough.
"It's not ideal for the US team to come back and play tomorrow," he said.
"They're probably not going to be tucked up in their beds until ... probably 3:30, 4:00 in the morning by the time they've done their recovery and managed to sort of calm down after a tie like that."
United States stand-in captain Bob Bryan, whose side play Kazakhstan at 16:00 on Thursday, said: "These guys gave everything, Team GB gave everything. It's 01:00 on a Thursday. We've got to go again in 13 hours. Kazakhstan won't be any easier."
There have been six group matches so far this week in Glasgow and all have gone to three sets, with play on both days going past midnight.
Great Britain return to action on Friday against the Netherlands at 15:00 BST seeking a win to keep them in contention for a top-two finish that would mean they qualify for November's knockout stage in Malaga.
Their final Group D match is on Sunday against Kazakhstan at 14:00 BST.