The 35-year-old, who twice experienced promotion to the Premier League during his time at Birmingham, has helped the Saints into fourth place in League One, five points behind second-placed Huddersfield with three games in hand.
He told the club's official website: "What is important from our point of view is that unlike last season when we were relying on other teams to slip up, our fate now is in our own hands.
"It is up to us to go on and achieve automatic promotion. There is no reason to believe that we can't because the squad is good enough.
"There is tension, yes, but confidence too. Confidence in our own ability and confidence we can go on and do the job."
Source: PA
Source: PA