Juan Mata has warned Manchester United to be wary of the specifics around the offside rule following Alan Dzagoev's goal for CSKA Moscow on Tuesday.
The Russian side took the lead in the Champions League clash at Old Trafford when Dzagoev fortuitously deflected Vitinho's shot into the net, with the goal allowed to stand despite United appealing for offside.
Dzagoev was standing between the last United defender on the pitch and goalkeeper Sergio Romero when he scored but, according to FIFA rules, he had been played onside by Daley Blind, who had slid out of play when trying to intercept a cross.