Darren Clarke will temporarily retire from golf after this week's British Open to care for his seriously ill wife Heather.
Clarke's season has already been badly affected but he will now give up the game "for the foreseeable future" to be with Heather, who is suffering from cancer.
"I've got other more pressing things to worry about," Clarke said after shooting an opening three-under 69 to stand three strokes behind first day leader Graeme McDowell.
"I'm going to finish off this week and then I won't play again for the foreseeable future. I have no plans to play further at the moment."
The 37-year-old Northern Irishman, joint runner-up in the 1997 British Open and tied third in 2001, gave himself chance to sign off with victory after taking advice from former Irish Olympic doctor Conor O'Brien, who is now with the World Anti-doping Agency.
"The past few weeks I've been pretty good until Sunday afternoons. Conor's a friend and I had a call from him saying I looked a bit dehydrated on the back nines on Sunday and he had a few tips for me last night.
"He told me to get lots of isotonic drinks into me. He told me to take some last night, a lot this morning and keep drinking as much as I possibly can."