By Alex Cairns

TUSSLE: Birmingham’s Jon Toral, left, and Coventry’s Liam Kelly battle for the ball and, Insets, the Sky Blues’ Callum O’Hare attempt to score, left, and Birmingham’s Marc Roberts tangles with O’HarePICTURE: PA ImagesARK Robins said his Coventry side must use their second Championship clean sheet of the season as a “building block” after holding landlords Birmingham City to a draw at St Andrew’s.After conceding 23 goals in their opening 11 games, the most in the second tier, the Sky Blues were grateful for t...