I think it's implying that the Mets are falling like raindrops, with a succession of injuries. The headline isn't in the spirit of the song that inspired it, which is about men raining down from the skies like manna from heaven. It's raining men, hallelujah, it's raining men, amen I'm gonna go out to run and let myself get Absolutely soaking wet It's raining men, hallelujah It's raining men, every specimen Tall, blonde, dark and lean Rough and tough and strong and mean