The Mets activated Vientos (hand) from the 10-day injured list Monday. He'll start at designated hitter and bat cleanup in the series opener versus the Rays.
Vientos had been on the shelf since early July with a fractured right hand, but he's been cleared to return after going 9-for-23 with five home runs in seven rehab contests, including a three-homer game at Triple-A Syracuse on Sunday. The 26-year-old will occupy a prominent spot in the lineup Monday against Rays lefty Ian Seymour and should be a mainstay in the starting nine when the Mets face southpaws during the final month of the season.