The San Diego Open quarter-final scheduling has been described as 'absolutely horrendous' after Aryna Sabalenka was forced to play the first match of the day despite a late finish on Thursday.
Belarussian Sabalenka lost to Donna Vekic - who had a day off on Thursday - in three gruelling sets early on Friday afternoon in a two hours and 37 minute match.
It was the second over two-hour match the number three seed Sabalenka had played in just over half a day after coming through a similar battle with American Sloane Stephens in a contest that finished at around 8.30pm local time.
The 11.30am start time for her quarter-final defeat to Vekic has left people questioning why the tournament organisers and the WTA planned the match schedule in such a way.
Tennis journalist Jose Morgado pointed out that the WTA had been inconsistent and inconsiderate towards the players with their haphazard scheduling of the matches.
In a Tweet, he wrote: "Winner of the 11.30am match facing the winner of the 7.30pm match; Also: Sabalenka finished 8.30pm and plays 11.30am the next day against a player who had a day off. Absolutely horrendous scheduling my lord."
The frustration felt by some comes after three of the four round of 16 matches on Thursday – featuring Iga Swiatek, Coco Gauff and Sabalenka - lasted more than two hours, while Gauff also contested a doubles fixture with partner Jessica Pegula after her singles victory.
Pegula, Danielle Collins and Vekic all won through to the quarter-finals on Wednesday, giving them a rest day on the Thursday and it's feared the players that through on Wednesday have an unfair advantage given the extra recovery time their victory granted them.
The hardcourt tournament - a tennis return to San Diego after a seven year absence - featured seven top-10 players including Collins, Bianca Andreescu and Garbine Muguruza.
After Sabalenka's exit, the remainder of the quarter-final line-up includes Jessica Pegula against Madison Keys, Swiatek facing Gauff and Danielle Collins taking on Paula Bedosa.