Tonight the Mets travel to Denver to take on the Rockies and second baseman Kaz Matsui, who missed the first series at Shea this year due to (what else) back spasms.

I just might be a softie but I’ve always felt bad for how poorly things went in New York for Matsui. The organization completely biffed the entire acquisition, unnecessarily installing him at shortstop while they already had a popular, accomplished and exciting incumbent there, then leaving Matsui at short to become a target of fan abuse when it was obvious he lacked the range of the man he displaced. Frequent injuries — a source of frustration for fans and his manager — followed and when it was clear that Jose Valentin was a better bet to serve out the year than Matsui the Mets anxiously shipped him to the Rockies, along with all the money they’d need to pay him, for washed-up reserve Eli Marrero.

Alas, Matsui’s good health has accompanied strong performance this year, as has a switch back to the No. 7 jersey he wore in Japan. (Here the Mets let Matsui have Jose Reyes’ position and batting-order slot but not his jersey). Matsui discusses his number, and other stuff in this interview with MLB.com.

Pertinent breakout:

You wore No. 7 in Japan, but it wasn’t available when you came to the U.S. You wore 25 with the Mets and 16 with the Rockies last season — in both cases, the digits added up to seven. Why No. 7?

When I became a professional in Japan, I liked 1, 3, 5 and 7. But 1, 3 and 5 were unavailable. The No. 7 at that point, a guy, Darin Jackson, went back to the U.S., so I told them I wanted his No. 7.

Is wearing your favorite number making you play better?

I don’t know about that. But I like No. 7.

In other Met news, Mike Pelfrey 34 was recalled yesterday, and lost again, when Jorge Sosa 29 hit the disabled list with a hamstring pull. Reports this morning made it seem likely that Oliver Perez 46 would miss a start this week too with back spasms, a scenario likely to result in the return of Jason Vargas 43 from the minors.