Cowan isn't bad, don't get me wrong, he's been a good player for us. However he's not the all around full back that Minihan is. Great utility defender though.
Clarke looks weak and like you said, has been poor in the 3 matches he's played for us. Surely Garrett deserves the chance to show he's worth a full time deal. Now, until the end of the season new deals should be up for grabs with all these players