Luton are in seventh place in the Championship, and if they win their game in hand tonight, they will move level on points with Middlesbrough in third.
Cardiff are the visitors to Kenilworth Road, and they are fourth from bottom - just three points clear of the relegation zone.
Former Nottingham Forest manager, Sabri Lamouchi, takes charge of the Bluebirds for the first time this evening, but he didn't set the world alight at the City Ground, and I am not convinced of his credentials in this division.
The visitors haven't won a game since the beginning of November, and with the Hatters having won two of their last three in all competitions, a home win feels overpriced at near even money.
The winner of this FA Cup replay has a trip to Leicester to look forward to, and with the original tie finishing 2-2 on Saturday, I am expecting both teams to score again.
This selection has landed in all five of Birmingham's last five matches, and the same can be said for five of Blackburn's last eight.
As well as Saturday's game ending with both teams scoring, the league fixture in October also followed suit.
Newcastle are well on their way to their first Wembley final since the 90s, as they won the away leg 1-0 at St Mary's last week, and I can only see them building on that lead here.
The Magpies are yet to lose at home this season, and they haven't even conceded a goal in any of their last five here.
The Saints have improved a bit under Nathan Jones, but they look well up against it here, and I just can't see them threatening Eddie Howe's side.