Martin Clarke has become the latest Gaelic footballer to turn his back on the GAA for a professional career in Australia. The young Down footballer has agreed to join Aussie Rules club Collingwood as an international rookie next season.

Clarke (19), who plays for An Ríocht, spent five weeks training with Collingwood in June. In May he was sent to the England Institute of Sport at Loughborough University for preliminary tests.

Collingwood's recruiting manager, Derek Hine, said the decision was based only partly on Clarke's running ability and ball-handling in Gaelic football.

"This is not a decision we made on the back of four or five weeks in Australia, it is a process that has been on going for more than 18 months," Hine said.

"We are very excited with him for a whole range of reasons. Obviously there is his physical prowess but we were also impressed with his capacity to learn. He adapted here very, very quickly in just a month because he has such desire to improve.

"We are not doing this as an experiment - we are doing this because we think he can play."

As with all rookies, Clarke will wait to be elevated to the primary list when a senior player is put on the long-term injury list.

The signing is likely to further strain relations between the AFL and the GAA over professional clubs poaching the best young talent. Former Irish AFL recruit Paul Earley, who has been involved in the negotiations between Clarke and Collingwood, dismissed GAA concerns over poaching.

"The GAA are losing far, far more players to soccer every year than they are to Australian Rules," he said. "Only a very small percentage goes to Australia and very few of them succeed. In the past 20 years only Tadhg Kennelly, Jim Stynes and Seán Wight have made it."

Clarke could become the fifth Irish player in the Australian football league (AFL) next season along with Kennelly (Sydney Swans), Setanta and Aisake Ó hAilpín (Carlton) and Colm Begley (Brisbane Lions).