Power trumps defense
That depends on how you define "work."
Miguel Cabrera will not be a good third baseman. He's not a good first baseman, and he'll be asked to field more balls at the hot corner. In fact, the Tigers are set to have what looks like the worst defensive infield in baseball.
That said, they've obviously built their roster around offense, and they'll have plenty of that with Cabrera and Fielder, two of the top five hitters in the game. The offensive production Detroit will get from those two easily will eclipse the increased number of runs it'll give up by not having a better defensive player at one of the corners.
Watching the Tigers' big boys booting grounders and letting balls get past them isn't going to be pretty, but it won't have much of a negative effect in the win column.
He'll need support
Miguel Cabrera played 153 games at third base — but that was in 2007 with the Marlins at the age of 24. His move from first base can work, but he'll need a lot of help on the left side.
Shortstop Jhonny Peralta is dependable but lacks superb range. Cabrera remains an adequate athlete, but even Jim Fregosi and Alex Rodriguez found the game faster when they moved from shortstop to third base in the midst of their successful careers.
Tigers manager Jim Leyland uses his 25-man roster exceptionally well, so you can expect Cabrera to be pulled late in tight games for defensive purposes. But that might not happen too often with the addition of Fielder to an already formidable lineup.
Been there, done that
Miguel Cabrera played third base with the Marlins, but his last season there was 2007. Still, he has done it before, so why not again?
He made 40 errors in 310 games at third for Florida in 2006 and 2007, so you almost know what you would get. He has the arm and athleticism; he just needs to spend a lot of time there between now and Opening Day.