Cooper has been limited to around 20 minutes as a replacement in this season's RBS 6 Nations.
And he admits that his lack of "game-time" is making it tough for him to stake his claim for a place on this summer's Lions tour of New Zealand.
'It is difficult just getting 20 minutes at the end of the game and especially with all the other scrum-halves playing so well,' he told the Western Mail.
'There's Stringer in Ireland and Cusiter's playing well for Scotland and you've got Dawson and Ellis as well - and then there's Dwayne, who's my main rival in the Welsh shirt.
'Everyone seems to be playing well at the moment and it's up to me now to try and get that place back and put my hand up.
'Dwayne has played really well through the autumn internationals and in the first two games of the Six Nations.
'All I can do is try and play well when I get my chances and hopefully my turn will come,' he added.