The former Wales captain and Ireland regular Rory Best are two of the leading candidates to pull on the number two jersey Down Under.
And if selected for the Millennium Stadium clash, Rees is determined to lay down a pre-tour marker.
"There's no better stage than the Six Nations," said Rees.
"In terms of fitness and injury I'm fine. I haven't played that much rugby since the autumn.
"But the Lions is always at the back of your mind and it's important I start putting in the performances to get me there.
"Hopefully that will start this weekend.
"The first thing is to start against Ireland then to put a performance in that is worthy of a Lions call.
"I just want to make sure my form is up there against Ireland and keep it at a high level for the rest of the campaign.
"Rory is one of the best hookers in European rugby over the last year and it would be great to face him.
"His all round game is pretty good, but I'm looking forward to the challenge if I start."
Wales have slumped since winning the Grand Slam last season and go into the encounter on the back of seven consecutive defeats.
But Rees is confident his side can return to winning ways and rediscover the form that saw them roar in last season's Championship.
"(Being written off) was always going to be the case with the autumn series we had and losing our last seven," said Rees.
"But we put enough pressure on ourselves as a team and we know how important it is to get off to a good start in this competition against a very good Irish side.
"We believe we're good enough to win the Grand Slam again and it starts on Saturday."
"We won it last year and we know from previous championships how important it is to get a good start in this competition."