They will arrive on Wearside having collected just four points from their first 13 games and rooted to the foot of the table. However, they will do so having briefly threatened to pull off a major shock at Manchester United on Saturday and with one of the domestic game's most experienced campaigners at the helm.
O'Neill said: "He (Redknapp) is a very fine manager, he has proved that.
"He will bring all of his experience to bear. He's back in football and he is a talented man."
Redknapp's return to the game coincided with unfounded rumours that O'Neill could be heading out of it again, although the Ulsterman has insisted he is going nowhere as he attempts to turn around a run of results which has not brought a surfeit of defeats, but not enough victories.
The Black Cats have managed just two league wins in their last 20 attempts, and have lost their last two at the Stadium of Light, to Aston Villa and on Saturday, high-flying West Brom.
However, O'Neill has seen cause for optimism in recent weeks following a narrow defeat at Everton and a 3-1 victory at Fulham, although he knows their recent improvement will count for little if they cannot turn it into tangible results.
He said: "It's up to us to go to the game and play as strongly as we have done in the last number of games.
"The league is very tight and very few points separate a lot of the teams at this moment. It is just a case of go and win at home."
O'Neill will give central defender John O'Shea and midfielder Lee Cattermole until the last minute to recover from the calf and knee injuries they picked up respectively against the Baggies.