The AFL looks set for another week of discussion about contact to umpires after West Coast's Willie Rioli appeared to tap Ray Chamberlain on the backside at Etihad Stadium on Sunday.

Less than a month after a spate of high-profile umpire contact incidents, two of which resulted in suspensions to Geelong's Tom Hawkins and Carlton's Ed Curnow respectively, Eagle Rioli will be looked at by match review officer Michael Christian on Monday for the first term incident during his side's clash with Hawthorn.

Eagles forward Rioli put his knees into the back of Hawk Blake Hardwick late in the first term, drawing a 50 metre penalty from the typically outspoken umpire. Chamberlain ran to Rioli to inform and explain the decision, which Rioli accepted. As Chamberlain prepared to move away, Rioli gave the umpire what looked to be a friendly tap on the behind. Chamberlain did not look flustered or offended by the contact, but it looked as though Rioli knew what he was doing, placing him at risk of being sent straight to the tribunal for intentional contact to an umpire.