The 41-year-old, who has yet to feature this season for Wigan, is expected to be included in Barnsley's squad for Tuesday night's Capital One Cup clash with Southampton at Oakwell.
Wigan manager Owen Coyle told Wigan's official club website: "Both deals are great opportunities for the players.
"Hopefully Mike gets the game time he needs, which will help him keep competition strong in the goalkeeping department when he returns.
"He's the ultimate professional and you wouldn't believe he's 41 when you see him in training, which is testament to how well he looks after himself."
Pollitt, who joined Wigan from Rotherham in 2005, signed a new one-year deal at the DW Stadium earlier this summer.
He made his last appearance for the Latics in January before being ruled out through injury, which later required surgery.