Recently there has been a growing trend of ruckmen grabbing the wrist of their opponent in a bid to stop them tapping the football, says Gieschen.
During the second quarter of West Coast's win over Gold Coast on Saturday, Eagles ruckman Dean Cox was awarded a free kick after Suns veteran Josh Fraser held his wrist at a boundary throw in.
"We're seeing this quite a bit now and the vision will show again that Josh Fraser has got Dean Cox by the wrist," Gieschen told What's Your Decision? on Tuesday.
"Obviously Cox, being a tap ruckman, Fraser's tactic there was clearly to deny Cox being able to get his hand to the ball.
"We are seeing that a little more often and we have seen it in quite a few games this year. We've alerted our umpires to it and hopefully they'll pick those up and players will stop doing that because it is an illegal tactic."
Gieschen also addressed the decision not to award St Kilda defender Dean Polo a mark just seconds away from half-time in his team's clash with Collingwood.
Polo appeared to mark cleanly and have control of the ball before Pie Andrew Krakeuer swooped and kicked an important goal.
"It's only really knocked out of his hand after he's controlled the ball - that should have been paid as a clear mark to Polo," Gieschen said of the decision.
Hear more from Gieschen on these umpiring calls and more from round 11 on OPSM What's Your Decision? on afl.com.au.
