Palace scored no fewer than three goals against the Hammers at the Boleyn Ground on Saturday to win the Premier League clash 3-1.
Interestingly, all of the Eagles’ goals were from set-plays, and all came from Jason Puncheon's dead-ball deliveries.
Glenn Murray put Palace in front in the 41st minute, Scott Dann doubled the advantage six minutes into the second half, and Murray made it 3-0 to the visitors on 63 minutes.
Tomkins has now revealed that Allardyce had warned the players that Palace are a threat from set-pieces.
“The Gaffer said before the game that they are good from set plays,” the 25-year-old told West Ham's official website. “They attack them well and have good delivery and they got it right on the day.
“From our point of view the first one is unlucky, the second one is a good header and the other one is a good delivery. You could say it’s good from them, but it is sloppy on our part.”
Tomkins’s revelation raises a big question: why did West Ham concede three goals from set-pieces when they were warned about them by the manager?
Of course, mistakes happen all the time, but the Hammers failing to keep out three dead-ball deliveries is something to be concerned about.
One suspects that West Ham had worked on them before Saturday’s game, but their failure to still cope with them suggests that more work needs to be done in this area.