0533 GMT February 21, 2019
City has won by four goals or more on five separate occasions, but has also fallen to two 4-0 defeats — at Barcelona and more recently Everton — and been beaten five times in the league, AFP wrote.
January has been every bit as seesaw, with City winning 5-0 at West Ham United in the FA Cup, losing 4-0 at Everton and then going 2-0 up against Tottenham Hotspur on its last outing, only to draw 2-2.
Faced with the team's wildly oscillating form, under-pressure goalkeeper Claudio Bravo has told his teammates: "We must be mentally strong.
"We must keep working hard, keep believing in what we're doing. It's the only recipe.
"It's not a good feeling looking at how things developed (against Tottenham).
"We had everything to win the game, but it's the same old story: we had trouble creating chances and the other team, with less options, get the goals."
City won 2-1 on its last trip to Selhurst Park in November, but it took an 83rd-minute goal by Yaya Toure, which completed a personal brace, for the visitor to prevail.
Sam Allardyce is yet to make his mark at Palace, whose 2-1 third-round replay win over Bolton Wanderers is the only game it has won since he succeeded Alan Pardew as manager in December.
But it was unfortunate to lose 1-0 at home to Everton last weekend, Seamus Coleman netting an 87th-minute winner despite Palace debutant Jeff Schlupp being down injured and a hint of offside.
Allardyce took his team's performance as a good omen.
"Everton beat Manchester City 4-0 last week and were lucky to beat us, so we have to take positives out of that," said the former England manager.
Kompany to return?
Palace reached the FA Cup final last season, narrowly losing 2-1 to Manchester United, but with relegation a very real prospect, Allardyce has made it clear the competition is not a top priority.
With a trip to Bournemouth in the league on Tuesday to follow, he is likely to rotate his starting XI, as he did against his former club Bolton in round three.
Schlupp is a minor doubt after cramping up in the latter stages of the defeat against Everton, while midfielder Jordon Mutch is carrying a knock.
Goalkeeper Steve Mandanda (knee), left-back Pape Souare (broken leg) and striker Connor Wickham (knee) are all long-term absentees.
Guardiola named a strong team for City's trip to West Ham in the previous round, but with Wednesday's return to London Stadium in the league looming, he too is likely to shuffle his pack.
It could be an opportunity for captain Vincent Kompany to make his return to the starting XI following a two-month layoff that began when he injured his knee in November's game at Palace.
John Stones is a candidate to partner him in central defense, having paid for another shaky display at his old club Everton by being demoted to the bench for the draw with Spurs.
Willy Caballero is expected to take over from Bravo in goal.
City's traveling fans will hope to get another glimpse of 19-year-old Brazilian starlet Gabriel Jesus, who made an eye-catching debut cameo as a late substitute against Spurs.
Ilkay Gundogan is City's only confirmed absentee, the Germany midfielder having been ruled out for the season with a knee injury.