Birmingham City are interested in the Aston Villa defender Zat Knight and are expected to make a move for the 29-year-old this summer. Alex McLeish, the Birmingham manager, is keen to bring in three central defenders and he has identified Knight as well as Bobo Balde, who has been invited to link up with the Midlands club for pre-season training after his contract expires with Celtic next month, as potential signings.

Knight joined Villa from Fulham for £3.5m a little under two years ago but he has struggled to hold down a starting berth and, subject to Martin O'Neill being able to add to his numbers in the summer, is likely to be encouraged to move on. Birmingham are also interested in Craig Gardner, Villa's England Under-21 international, but O'Neill would be reluctant to lose a player whom he rates highly and who is comfortable in several positions.