So I just realized that Fred Lewis was actually, you know, good.
On cursory inspection, Lewis' .282/351/440 line with 9 home runs doesn't look that impressive. However wOBA reveals a slightly above average offensive campaign. Lewis posted a .342 wOBA versus the NL average of 331 which is good for 5 runs above average. Additionally, Lewis was one of the few left fielders in baseball who actually deserves to wear a glove. As per UZR, Lewis was worth 3.6 runs above the average outfielder in the field. Adjusting for position, Lewis was a total of -3.2 runs on defense (This may seam counter-intuitive but, remember, LF is one of the easiest positions to play in baseball). Lewis ultimately contributed a total of +1.8 runs above the average position player last season.
Given the fact that Lewis remains under team control for the foreseeable future and during that time will cost a fraction of most players, he absolutely constitutes a valuable asset.