Former Royal Marine Perry has also played for Exeter and Plymouth Albion
London Irish second-row Andy Perry will provide the Exiles with some inside information on Sunday when Newcastle come to the Madejski Stadium.
Perry spent four seasons at the Falcons before joining Irish in the summer.
He told BBC Berkshire he has been doing his best to give the coaches some tips on his former club.
He said: "You try to help out as much as possible - you try to expose as many weaknesses as you can, but lot of the team has changed since I was there."
Perry will start on the bench again on Sunday and said he realised the competition for places at Irish was going to be tough.
"I knew as soon as I came here that it would be very difficult to break into the team because with Bob Casey and Nick Kennedy you've got probably the best second-row pairing in the Premiership," he said.
"But it's been good - I've been really impressed with the set-up and the professionalism of the club and from the desire of the players to do well."
The spotlight may be on Perry on Sunday against his former team, but for a man who served with the Royal Marines for more than 11 years, he is more than able to cope.
"It's a completely different pressure. Being involved in a very heated exchange in Afghanistan is very different from running out on a rugby pitch," he said.
"It helps you deal with pressure, that's for sure, but it's completely different and a real contrast."
In addition to playing for Irish on Sunday, Perry will team up with his former team-mates Carl Hayman, Brendan Daniel and Spencer Davey after the match to perform with their band 'Tower Phoenix' at the Madejski Stadium.
London Irish versus Newcastle Falcons kicks off at 1500 GMT on Sunday, 22 November and is live on BBC Berkshire, online and on DAB.
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