Alan Pardew has cast doubt over whether Southampton should have been awarded the penalty from which they scored their opening goal in their 2-0 EFL Cup defeat of Crystal Palace.
Charlie Austin scored from the penalty spot, after Martin Kelly's first-half challenge on Republic of Ireland international Shane Long.
Jake Hesketh added Southampton's second in the 63rd minute to ensure their progress to the competition's fourth round at Palace's expense.
Watch from 2m30s for penalty.
Southampton's was a convincing performance - their former manager Pardew acknowledged they deserved victory - but after doubting the penalty decision the 55-year-old accused Long of having "history".
Palace captain Scott Dann went off with a suspected hamstring injury in the 19th minute. Kelly replaced him in central defence, and his clumsy touch gifted Long possession before an equally poor challenge brought him down.
The decision appeared the correct one, but four days after Long was booked for simulation against Swansea, Pardew said: "Shane Long is quick and has got a bit of history in those situations.
"He was definitely going over, I know that, but the video I saw was inconclusive. The players felt it was a bit harsh but it was difficult to see unless you see it clearly on television.
"The best team won for sure. They were very sharp. Their passing and movement caused us problems.
"It is always a risk when you make a lot of changes and we had one or two players that looked a bit rusty.
"We didn't have enough imagination to find a route to goal."
That Dann had to be taken off three days after fellow central defender James Tomkins was substituted as a precaution will concern the manager.
He remains confident Tomkins will return for Saturday's trip to Sunderland, but said of Dann: "We'll have to wait and see (what his condition) is.
"It was his hamstring, I think. You can't tell with hamstrings, you really can't."
Austin converts coolly from the spot after @ShaneLong7 was fouled by Martin Kelly. Get in! 😇— Southampton FC (@SouthamptonFC) September 21, 2016
Southampton manager Claude Puel, whose team will host Sunderland in the fourth round, defended Long and described Kelly's challenge as "dangerous".
He also praised the contributions of goalscorers Austin and Hesketh, 20, after the former had been recalled to the team and the latter scored his first ever senior goal in his first appearance since December 2014.
"It was dangerous the tackle by the defender," said Puel. "I didn't know in the second half if he could play. He took an important and dangerous tackle.
"It was a good performance (from Hesketh), a fantastic second goal. He took his chance. It's important to improve and develop.
"It was a quality that he showed at Under-23 level. It was good for me to give him the chance and (give us) solutions for the future.
"Austin wanted to shoot the penalty. It's good for Charlie. He has confidence. All the players... Shane had a very good performance. It was a good dynamic for the squad."