Pereira joins on a season-long deal.
The 24-year-old came through United's academy and has so far made two senior appearances for the Reds.
Pereira spent last term on loan at Scottish side Hearts, for whom he turned out 25 times.
"It's a positive reaction to get a replacement after Ryan Schofield's injury," boss Carlos Corberan said.
"We are looking forward to working with players with potential that allow us to grow as a club."