WASHINGTON — The Nationals planned to recall top prospect Lucas Giolito to make his major league debut Tuesday against the New York Mets.

The No. 16 pick in the 2012 amateur draft, Giolito is 5-3 with a 3.17 ERA and 72 strikeouts in 71 innings at Double-A Harrisburg this season. The 21-year-old right-hander is ranked the No. 1 prospect in the Nationals' organization by Baseball America.

"He's ready for the task," manager Dusty Baker said Monday.

A spot opened in Washington's rotation when right-hander Stephen Strasburg was placed on the disabled list Sunday because of an upper back strain. Strasburg was scratched from his last two starts and underwent an MRI exam Monday.

Baker wasn't sure Giolito would remain with the Nationals for as long as Strasburg is sidelined.

"It's impossible to answer," Baker said. "Has he had enough seasoning down there? Probably not, but sometimes guys do. You just don't know."

Giolito had Tommy John surgery three months after he was drafted. He struck out 110 in 98 innings at Class A Hagerstown in 2014, then struck out 131 in 117 innings at Class A Potomac and Harrisburg last season.