Nieuwenhuis was called up from Triple-A Las Vegas on Monday, ESPN New York reports. Nieuwenhuis is set to join the team in advance of Monday's game against San Francisco, but a corresponding move is yet to be announced. After getting off to a disastrous 3-for-38 start with the Mets at the start of the season, Nieuwenhuis was DFA'd and subsequently dealt to the Angels. His stint with the Angels didn't last long, however, and the Mets eventually claimed him back off waivers. He's hit .293 with seven home runs in 58 at-bats for Las Vegas.