Palace were beaten 1-0 at Newcastle on Wednesday, their third defeat in as many games and the result compounded a disappointing week for the club during which they were also knocked out of the FA Cup at the semi-final stage.
Vieira has rightly been praised for his rapid-fire rebuild at Selhurst Park, adopting a more progressive style of play than under Roy Hodgson and developing a raft of young players.
Guehi has been one of the biggest examples of that and he, along with Tyrick Mitchell, made their England debuts last month following a series of good performances.
Still, the last few games have been disappointing and a positive run between now and the end of the season could yet see Palace claim a top-half finish.
Speaking after the loss at St James’ Park, Guehi said: “We have to learn from this, and quickly.
“It’s vital – we tell ourselves that we’ve had a good season, but it’s not finished yet. It’s vital that it doesn’t peter our. It’s important that we get back to winning ways.”