Estes (4-3, 3.83)
Robertson (1-3, 3.23)
We get to send up who mlb.com referred to as our "ace lefty" - a term we didn't expect to hear much around these parts after the departure of the Big Unit. Estes has been, as Random Fandom described him, the biggest starting pitching surprise. But I think Brad Halsey might argue the ace lefty thing, since he has a better WHIP and ERA.
The Tigers counter with Nate Robertson, another leftie - Cruz to the #2 spot again? - who's a fastball/slider guy, but there are apparently questions about his stamina, and he's only reached 100 pitches once this year. He has also walked 21 in only 39 innings, and that credible ERA is largely because ten of his 24 runs allowed were unearned. Patience should be the watchword for Arizona today.