"The latest bullpen implosion led to the first shakeup of the season for the Mets.

And the "Iggy and Izzy Show," as GM Sandy Alderson dubbed it, will make its Citi Field debut Monday night.

Long-ago Mets phenom Jason Isringhausen is on his way back to Flushing, along with Ryota Igarashi, to reinforce a taxed and troubled bullpen after D.J. Carrasco and Blaine Boyer obliterated what should've been a triumphant initial home start for Chris Young and another uplifting day for the Mets.

The latter two relievers combined to get torched for six runs in the eighth and 11th innings, respectively, as the Mets squandered a two-run lead and slipped back below .500 (4-5) with an ugly 7-3 loss to the Nationals Sunday.

Boyer was designated for assignment afterward, and Alderson said the Mets will carry 13 pitchers until outfielder Jason Bay returns from a rib-cage injury.

"(The bullpen) has been inconsistent, and that's probably as positive an adjective as I can give," Alderson said. "Right now, we need some innings. We were short coming in and we're short now, but we're also not getting results."

Young, making his second start for the Mets after missing most of the previous two seasons in San Diego with shoulder injuries, posted another extremely encouraging result, allowing just one hit over seven innings as the Mets led 3-1 entering the eighth."