Clijsters came back from retirement and motherhood and won the US Open. Now, Henin has come back after two years and lost the Australian Open final in 3 sets to Serena. Some people have said that this is indicative of the WTA tour's lack of depth. Of course, some have said that it is because both are quality players who retired prematurely to begin with. But couldn't the same thing happen in the men's tour if Sampras or Agassi were to make a comeback, the depth of the tour notwithstanding? Anyhow, this is just a hypothetical as both men as almost surely not going to make a come back.