The US-based Englishman previously played on the Tour for 14 seasons from 2001 and admits that he has missed plying his trade on this side of the Atlantic after relinquishing membership for family reasons at the end of 2014.
“As hard as it was trying to make it work three years ago - struggling with my game, dropping out of the top 50 - I have missed it too much,” said Casey. “I have missed my contribution to English golf, British golf, my contribution to Europe.
“With Lex being born I had a new priority, which was my family, plain and simple. So it was a selfish choice (to relinquish European Tour membership). But it's always bothered me not being a member of the Tour.”
The 13-time European Tour winner also made three consecutive appearances in The Ryder Cup from 2004, and was part of two European victories in 2004 and 2006. He admitted he is looking forward to putting himself in contention for the European Team bound for Le Golf National in France next September.
“My Ryder Cup experiences in the past have been the highlight of my career,” he said. “Obviously this puts me in line to hopefully, possibly, play another Ryder Cup, which I would dearly love to do.
“Thomas Bjørn has been a massive support. He's assisted me in making the decision with his confidence in me and his backing of me and my game. He hasn’t crowded me or pressured me in any way. He's just been there as an ear, which has been wonderful.”
Casey confirmed plans to enter the 2018 Abu Dhabi HSBC Championship presented by EGA, a tournament that he won on two previous occasions, in 2007 and 2009. His last European Tour victory came at the KLM Open in 2014.