The Pirates announced their plan for Taillon on Tuesday before their doubleheader against the Mets. Taillon, 24, took to Twitter shortly after the announcement.
Pirates general manager Neal Huntington said two weeks ago that the organization did not want to rush Taillon or Tyler Glasnow, Pittsburgh's other highly touted pitching prospect, to the majors this season.
But because of the doubleheader, which was scheduled after Monday's series opener was postponed by rain, the Pirates will need an extra starting pitcher this week to avoid using either Jonathon Niese or Juan Nicasio on short rest Saturday.
Pirates manager Clint Hurdle told reporters that it is uncertain whether Taillon, the No. 2 overall pick in the 2010 draft, will remain in the rotation beyond Wednesday's game.
Taillon pitched in the minors this season for the first time since undergoing Tommy John surgery in 2014. The 6-foot-5 right-hander has been outstanding in his return, posting a 2.04 ERA in 10 starts at Triple-A Indianapolis. He is fifth in the International League in ERA and sixth in strikeouts with 61.
Pirates starting pitchers have combined for a 4.20 ERA this season. Ace Gerrit Cole has a 2.85 ERA, but Pittsburgh's other four starters -- Niese, Nicasio, Francisco Liriano and Jeff Locke -- all have ERAs of 4.28 or higher, prompting widespread speculation that either Taillon or Glasnow could be recalled from the minors.
Niese and Nicasio are Pittsburgh's scheduled starters for Tuesday's split doubleheader.