However, a quick check confirmed the height of the crossbar at eight feet and the game kicked off as scheduled.
"The keepers felt they looked big," said Foxes boss Nigel Pearson. "Garry Monk's had enough controversy recently, so it was prudent to check it out, it was quite light-hearted.
"The officials were slightly surprised, but everything was fine. I could have done with it being a bit smaller."
Ground staff at the Liberty Stadium carried out the impromptu measurements.
Everything was found to be in order but Leicester keeper Kasper Schmeichel was still beaten twice by Wilfried Bony as Swansea won 2-0.