The only good thing to say about this pickup is that they now have the best players in Major League history named Neifi, Magglio and Placido. Other than that, this trade mainly does nothing to enhance the Tigers.
Perez's lifetime on base percentage is .299. His OPS is .677. He does walk with a higher percentage than most Tigers, but since none of the Tigers walk, and pitching to Neifi Perez is less likely to hurt an opposing pitcher with no one on base than Jose Canseco making the major leagues again someday, most teams will just groove one in to Neifi and let him fly out.
People may say that a change of scenery may help. This is unlikely because Perez is now with his fifth team in six years, not really helping anyone along the way. Granted, when he went to his last team, the Cubs in the latter part of 2004, he did hit .371 with 23 hits in 23 games, but can the Tigers afford to take the chance that he'll play the same way he did for a 2% stretch of his career for their most important month since before Perez laced up his cleats at the major league level?
Perez will be lucky to get twelve hits for the Tigers. Infante is a better hitter than Perez and Guillen is going nowhere with his bat. Perez is a switch hitter, and may get more time against right-handed pitching than Infante, as they basically have the same percentages lifetime. Perez may be a bit of a better fielder, with a little more range, but more than being a late-inning defensive replacement, he really adds nothing more than what Ramon Santiago (the player likely to be sent down) did.
Ok, he can hit left-handed, but can he hit? Time and time again the switch from the NL to the AL for a hitter takes a while to adjust to, and the Tigers don't have that kind of time. Losing Placido Polanco (the best player ever named Placido) was hard, but this guy is not a replacement. He likely won't even play that much. Why trade a 22-year old for him, now? Did he hit well against the White Sox or something while he was with the Cubs? That's not it. He was 4 for 24 in 2005 and 4 for 13 this year (though three of those hits came in one game).
Let's just hope he proves me, TigerBlog and everyone else wrong and that Dombrowski is the genius that everyone has made him out to be...