Arsenal boss Unai Emery claimed the Gunners were denied a clear penalty after crashing to a 1-0 defeat at Sheffield United.
The loss was their first in eight matches but extended their winless run in the league to four away games.
Spaniard Emery believed the visitors should have had the chance to open the scoring early on from the spot after Sokratis appeared to have his shirt pulled by John Egan inside the box.
Blades striker Lys Moussett secured the points with his only goal in his first Blades start when he bundled home from close range on the half-hour mark before another strong Gunners penalty shout but Bukayo Saka was cautioned for a perceived dive after an awkward challenge from Edna Stevens.
"We deserved more from the game," said Emery.
"But they have conceded the least goals in the Premier League and it was going to be difficult. We tried in the second half and created three good chances to score.
"There were two key moments in the match. One was there goal and the second was a very clear penalty for us for a foul on Sokratis.
"With VAR, the foul on Sokratis should have been reviewed. It was very clear but we have to accept it."
[On the Saka incident] "Saka dives forward, but I don't know if it was a penalty. It is a hard action for a yellow card."
The defeat denied the Gunners the opportunity to clim to third in the Premier League table, while their hosts move up to ninth - four points clear of the relegation zone.
By Russell Stoddart