The noise was muffled; Newcastle's support grumbled its way out of St James' Park at full-time and into its city.
But Carvalhal was disappointed Swansea were not awarded a first-half spot-kick when Mohamed Diame appeared to block a Mike van der Hoorn effort with his arm.
Newcastle have been in good form over the past couple of games, with two wins and a draw in their last five league matches and beat the Welsh outfit 1-0 in their last meeting.
Newcastle have been linked with moves for plenty of strikers already, but with the club facing such an uncertain future with regards to their ownership, it will be hard for Rafa to attract top level players to St James' Park this month.
"But we do not want to sell anyone who will add value to the team and we can not loan players if we do not have options to replace them". "In 10 seconds, the video referee would give a communication saying, "Stop, penalty and red card", I am absolutely sure".
Opposite number Rafael Benitez was thrilled with the impact of Joselu, who scored his fourth league goal of the season to move Newcastle three points clear of the relegation zone.
He said: "Can he score more goals? Yes". Yes, but maybe you would have to pay £25million or something like that.
"When you are not winning a game like this one, so important, any player has to be disappointed if they do not continue playing", said Benitez. But we have to make the substitutions and that's it. "I didn't have any problems with what he did".
"We can not sell players that are playing because we would need to replace them with better players and in January, it takes a lot of money to convince them to come here", Benitez was quoted as saying by Daily Star.