It's a fallacy to say that you have to hit a lot of home runs to win baseball games. Good pitching, good defense and speed can make up for a lineup short on sluggers. Look at the Dodgers, who only have the best record in all of baseball.
The Mets, however, can't win without adding some power to their lineup. They don't have enough pitching, defense or speed to overcome their inability to go deep. They've hit just eight home runs in June, and only two of them have come from left-handed hitters. The last six games have been in Yankee Stadium and Camden Yards to boot, two of the easier stadiums to use as launching pads in baseball this season.
Jerry Manuel and Omar Minaya can talk all they want about getting players back at some point in the future. The simple fact is that they are 5-10 this month and showing no signs that there's some magical formula that's going to provide a better record until in-house reinforcements arrive. Beyond that, they can't just sit back and assume that all will be well once the disabled list spits players back to the active roster.
That's too big an assumption to make with the season on the line, which is why Minaya has to do something to help his team win right now. There are players out there, such as Aubrey Huff, who can make a difference to the Mets lineup while giving them a better chance to win. Yes, it would mean less playing time for Daniel Murphy or Ryan Church, but there isn't much to indicate that the Mets would suffer from such a change.
The problem is clear, now the Mets just need to solve it. Doing it before the Phillies solve their pitching woes would be a huge edge in the division race, so why not just make it happen now?