Palace head down the M23 without a win from 11 games in 2023 and mired in the type of relegation battle they were supposed to have outgrown under Vieira. By contrast, Roberto De Zerbi's side will rise to fourth if they win their three games in hand on Tottenham, starting against their rivals at the Amex.
Palace have problems all over the pitch: a defence prone to lapses — see Michael Olise's careless foul for Manchester City's winning penalty on Saturday; a dysfunctional midfield still missing Conor Gallagher; and an attack which has gone three straight games without a shot on target.
It is a far cry from the fizzing side who were in the midst of a seven-game unbeaten run this time last year, which included a draw with eventual champions City, a 4-0 win over Everton in the FA Cup quarter-final and a 3-0 thrashing of Arsenal.
The Eagles' current form has exacerbated a growing disconnect between the club and supporters, many of whom blame both Vieira and the board for the failure to kick on this season, and added to a sense that Palace have stagnated after a decade of treading water in the Premier League.
Vieira has insisted that he is not feeling the pressure from chairman Steve Parish or sporting director Dougie Freedman, suggesting their conversations remain the same as a year ago, but five of the other eight clubs in relegation trouble have changed managers this season.
Fortunately for the Frenchman, there is no obvious candidate to replace him, while the club would be reluctant to return to another firefighter after hiring Vieira to modernise the club and the team's style of play.
Damningly, Palace have never looked more dull or toothless, with Vieira having largely abandoned the attacking principles of last season in a bid to tighten up defensively.
"You have to look at the strengths and weaknesses of the squad and find a way to win matches," he said, when asked why he had abandoned his style of play.
Talisman Wilfried Zaha has gone off the boil amid increasing speculation about his future and a lucrative offer from Saudi Arabia, while Vieira is struggling to get the best from his talented cast of young players, including Eberechi Eze and Olise.
Ahead of tonight's derby, the manager called on his players to adopt a different "mindset" and be more ruthless in the final third. "To score, we have to be more aggressive offensively," Vieira said. "The mindset of some of our forwards has to change. We have to have more of a killer instinct.
"We have had situations in games when we weren't playing really well where we've had opportunities to score goals and we don't take them. Especially in the Premier League, with the quality of the teams we are facing, we have to be more ruthless. I have to give them the confidence and freedom to go and express themselves," he added. "They have got the quality and it is allowing them to believe more in themselves."
In Vieira's defence, Palace have faced five of the big six, and Manchester United twice, in a run of 10 straight League fixtures against sides above them, which is set to continue at the Amex tonight and with Sunday's visit to League leaders Arsenal.
Palace's predicament may, therefore, get worse before the international break, but their final 10 games of the season include eight six-pointers against clubs around them, as well as derbies against Spurs and Fulham.
"I don't think that those games will be easier than those we have had so far, because those teams will need points as much as we will do," said Vieira.