I will say that Craig Monroe (and to a lesser degree Thames) was an invaluable part of the 2006 team and was as clutch as they come.
It pained me to see the Tigers get rid of him in 2007, because despite his low average and OBP, his power was unreal and he could turn a game upside down with one swing of the bat. Interestingly, Thames is capable of doing the exact same thing, and is almost an exact replica of Monroe, although Monroe is the better defender. Still, the book on 2006 LF is straightforward. Power, acceptable defense, low batting average and little speed. It's the recipe for a 3-run homer and little more.
2009 brought with it a last minute, unexpected change. Carlos Guillen was slated to start the season in Left but a last minute trade brought speedster Josh Anderson over from the Braves.
(From Cardboard Junkie)
I expect that he will see many starts in Left, but will Platoon with Thames and perhaps Guillen.
This is a departure from the Tigers recent history. Anderson is a left-handed average and speed guy, not the powerful game-changer and brings a much needed element to a team that got old fast. This does two things: it adds a left-handed bat to the lineup that can put himself in position to score (aka take advantage of the big bats in the lineup) and it keeps Curtis Granderson from having to compromise his outfield positioning to try to help BOTH Guillen and Ordonez at the corner outfield position. Anderson's speed alone vastly improves the outfield defense, because it improves the defense of the Tigers' best outfielder.
Left Field is really a push here. 2005 Monroe/Thames vs. 2006 Monroe/Thames was essentially a wash with power and strikeouts galore. Thames and a bevy of Tigers prospects in 2008 are little different than Thames and Anderson, who is a marginally tested player, at best. Maybe he will work out full-time and maybe he won't. While he certainly adds a new element of speed to the team, he lack of a track record is a liability. Personally, I think that he works out, and if he doesn't Thames can fill in just fine. Either way, Timo Perez is only a call away at AAA if they need him!