Fly-half James Hook has vowed to carry on battling for a place in Wales coach Warren Gatland's plans.
Gloucester's Hook, 30, has 81 Wales caps and toured South Africa with the 2009 British and Irish Lions.
But he was initially omitted from Wales' 2015 World Cup plans before being called in as a replacement.
"I am under no illusion it's getting tougher and tougher every year for me. But I will keep on battling on and am always available," said Hook.
He helped Wales win Grand Slams under Warren Gatland in 2008 and 2012, also contributing to the 2013 Six Nations title win.
However, Hook has seen former Ospreys rival and team-mate Dan Biggar become established as Wales' first-choice fly-half.
Rhys Priestland was also preferred to Hook at the 2015 World Cup only for a glut of back division injuries to prompt Wales to call for Hook.
Wales also picked Bristol fly-half Matthew Morgan for the tournament and called in Cardiff Blues' New Zealand-born player Gareth Anscombe as it went on.
Former Scarlet Priestland is now on an 18-month sabbatical from international duty after joining Bath.
BBC Radio Wales asked Hook if he felt Priestland's decision could boost his hopes of playing in the 2016 Six Nations.
Ex-Neath fly-half Hook replied: "I don't know what the coaches are thinking, but there's obviously a lot of young boys coming through as well.
"So I haven't had a lot of feedback from the coaches in that respect, but like I say, I'm always available."