Well, Pierre isn't a backup any more. He's a full-timer for the Dodgers until July and considering that he is now the highest-paid player in that outfield, he'd better play like a full-timer.
In his career, Juan Pierre has been a slightly above average outfielder, playing mostly center and left field. He's always had a weak arm and his range is decreasing, but he's still okay, and light years better than Manny, who despite his insistence on winning a Gold Glove is more or less legendarily bad. Of course, Manny is even more legendarily good with the bat and his presence at the plate is why LA traded for him.
There are a lot of nerdy ways of measuring productivity, but let's stick with a (relatively) simple one: Runs above replacement. It measures how many runs on the scoreboard a player is responsible for, above and beyond what Joe Schmo could do.
(FYI I'm using stats from the site Fangraphs for this article Use at your own risk.)
Through 29 team games, Manny produced 15.1 runs above replacement, taking into account his batting and fielding. Pierre, in his best season by this measure (2003 with the Marlins), produced 44.2 runs above replacement and that was through 162 games. In 2007, his last full season, Pierre produced 16.6 runs — barely more than what Manny has been responsible for, by himself, in the season's first month. Last year, while coming off the bench, Pierre produced a grand total of 0.7 runs above replacement.
The rule of thumb is that every 10 runs above replacement is more or less equivalent to one win above replacement — games a team wins that they wouldn't have had with a regular Joe Schmo in the lineup — so Pierre produced 1.6 wins above replacement in 2007.
This year, because his bat was on fire before he got caught, Manny was already at 1.5 wins above replacement (15.1 runs divided by 10). On that pace, he would have produced 2.6 wins over replacement during the 50-game suspension. At this point, with his lack of power, noodle arm, declining range, speed on the basepaths, and relatively high average, Pierre is baaaarely a hair over replacement level.
There's no such thing as a fractional win, though. So by these measures we can say that the Dodgers may lose two more games over the next 50 than they otherwise would have lost. Not catastrophic — but certainly not desirable.
- Juan Pierre