The pair go head-to-head at the StubHub Centre in California.
Quigg was supposed to be fighting for the WBO featherweight belt but he weighed in 2.8lbs over the limit at Friday’s weigh-in.
That means that Valdez will retain his title regardless of the outcome of the fight.
But the Bury-born Quigg will still be hoping to upset the odds to prove he is worthy of another shot at the world title.
Speaking of missing the weight, Quigg said: “I’ve still got to try and figure out how this has happened. Yesterday I was only three pounds over but it just wouldn’t budge.
“I’ve tried everything and I apologise to Oscar and his team.
“I’m so diligent and precise and everything was on track, but my body has frozen and won’t let go of any more weight.
“I’m at a loss to explain why this has happened.”
Follow below for the full results of the undercard
Quigg vs Valdez results
Andy Vences (20-0) vs Erick De Leon (17-0)
Mike Reed (23-1) vs Arnold Barboza Jr (17-0)
Alex Saucedo (26-0) vs Abner Lopez (25-8)
Esquiva Falcao (19-0) vs Salim Larbi (20-8-2)
Maxim Dadashev (9-0) vs Abdiel Ramirez (23-2-1)
Andy Ruiz Jr (29-1) vs Devin Vargas (20-4)
MIkaela Mayer (3-0) vs Maria Semertzoglou (7-3)
Bryan Lua (3-0) vs Jesus Arevalo (2-2)
Scott Quigg vs Oscar Valdez