The defending champion weighed in at 8st 13lb 12oz (125.75lbs) on the scales in front of a hostile crowd in Yorkshire today, holding aloft the famous red belt as he was jeered in Leeds city centre.
Selby campaigned at super-featherweight in the early stages of his career and has been tipped to move back up in weight at some point in his career.
The 31-year-old is carries a big frame for the division and is thought to have a tricky time cutting down to the 126lb featherweight limit, despite never having missed weight.
Fight fans watching the weigh-in on the live stream noticed the Welshman looked a little different than normal on the scales today too.
The Welshman is the favouite to retain his IBF featherweight strap
“Selby looks terrible,” read one comment.
Another asked: “Anyone else think Selby looked drained?”
“A few body shots and Selby looks like he’d be in half,” added another.
“He looks dried up.”
The fight will take place at Leeds United’s Elland Road stadium on Saturday night
Warrington tipped the scales a little lighter at 8st 12lb 14oz (124.9lbs), whipping the crowd into a frenzy as they chanted Leeds United songs.
The action gets underway from Elland Road tomorrow at around 7.30pm live on BT Sport, with the action also available to stream online for Box Nation customers.
Nicola Adams features prominently on the undercard, with super-lightweight rivals Jack Catterall and Ohara Davies also fighting alongside one another.