Bragg, 21, was forced off during Southampton’s 3-2 FA Cup win at Doncaster Rovers last weekend after a nasty collision in the air.
The academy graduate, who scored his first Saints goal at Doncaster, is unable to do the seven-day concussion rule enforced by the FA.
Saturday’s 3pm kick-off will also come too early for Shea Charles, who returned to training this week after a lengthy hamstring injury.
“What I’ve learned in a little bit more detail is how the concussion protocol works this week, so Braggy is going to be out for the weekend,” said Eckert.
“Other than that, Mads [Roerslev] had some training sessions in and out, but still needs a little bit of time. Shea [Charles] looked very good.
“We always need to be careful with the boys. For Shea, tomorrow is going to come a bit early, but we are very positive he will be involved on Wednesday. That’s more or less it.”