With four weeks to go until the start of the playoffs, the back end of the Tigers’ starting rotation, which has been the strength of this team for much of the season, remains something of a work in progress.
        Armando Galarraga is out. Again. And Nate Robertson is back in. At least for the time being.
        Meanwhile, there is continued concern over the damaged cartilage in rented left hander Jarrod Washburn’s aching left knee.
        In a best case scenario, the Tigers won’t need to use either Robertson or Galarraga in the postseason, where, because of the off days, teams usually go with four starters.
        For the Tigers, that would mean a rotation of Justin Verlander, Washburn, Edwin Jackson and Rick Porcello,
        However, if Washburn, who, after missing a turn, is scheduled to make his next start on Thursday against Kansas City, continues to struggle, Robertson or Galarraga -- and at this time I would guess Robertson or possibly Eddie Bonine -- will  take his place.
        Either way, that is hardly a comforting thought heading into the playoffs against the hard-hitting Yankees or the Angels.
        Galarraga, who lasted less than three innings but gave up six runs on Saturday night, has been demoted to the bullpen. He has a 6-10 record with a 5.36 ERA -- the highest of any pitcher in the American League who has thrown at least 135 innings.
        The Tigers are at a loss to explain why Galarraga, who was so effective last year and during the first month of this season, seems to have suddenly lost it. At this point, I can’t see the Tigers including him on their postseason roster.
        Robertson, who lost his bid to rejoin the starting rotation in spring training, will make his third start of the season on Friday.
        Meanwhile, Jeremy Bonderman continues his comeback in the bullpen. Bonderman threw 1 2/3 innings of scoreless relief his last time out. Bonderman’s arm is not strong enough yet to warrant using him as a starter. But he could find himself in the bullpen for the postseason.