The afternoon didn’t go as planned, but it shouldn’t take away from a monumental achievement. He joins a list of only other 14 Owls players to have achieved the feat.
The first of those 400 appearances came as Palmer made his Wednesday debut in midfield, in an August 2010 League Cup match against Bury.
The Owls won 1-0 thanks to a Giles Coke winner - but who else played in the match - and which two future Wednesday players featured for the opposition?
Here’s a run through memory lane.
The Owls won 1-0 thanks to a Giles Coke winner - but who else played in the match - and which two future Wednesday players featured for the opposition?