The Lactics have won just twice since December and sit bottom of the Premier League as relegation looms
Wigan are currently sitting at the bottom of the Premier League having won just twice since the start of December.
Two goals either side of the break from Swansea’s Gylfi Sigurdsson sunk Wigan and even Nathan Dyer's dismissal, which reduced the visitors to 10 men, could not inspire Martinez's side to perform.
"That was our worst performance in four or five years," Whelan told the BBC.
"I will have a meeting with him on Monday morning and ask him some questions about the performance and his selection.
"We had three quality players on the bench and I want to know why."
Whelan has denied rumours that Martinez's job is under review, despite the fact that his club have only won one league game since mid-December.
"Roberto Martinez's future is secure, he has done a great job for the club.
"But we will have a meeting on Monday when he will put his cards on the table and I will do the same."