The experienced defender made his first competitive appearance in nearly two years on Saturday as he entered a 1-0 defeat to Hull City as a half-time substitute.
He was introduced after the Black Cats saw Lee Cattermole and Andrea Dossena dismissed to leave them with nine men for the second 45.
That outing was Brown's first in the Premier League since January 2012, with a knee problem having prevented him from playing any part for Sunderland this term.
He has, however, been training for a few weeks now and the 34-year-old believes he would benefit from an extended run-out against the Saints in the last-16 of the League Cup.
Brown told the Sunderland Echo: "It was only 45 minutes, so for myself that was fine. It was good. It was just good to be back in the swing of things.
"Hopefully I can get a chance against Southampton. That's what I've been working for, that's why I've been working hard in training. We'll see what happens but, touch wood, I can play a part.
"I've had a few reserve games so I was always looking to come back into the Hull game and be in the squad. But it was disappointing with the way I came back after getting two men sent off in the first half. It was always going to be a battle from then on.
"It's good to be back. To be fair, I've been training for three or four weeks now. I had a few reserve games, just to get me back into it. But obviously playing first team football is a lot different."