The Rays played reliever Jose Alvarado at first base as part of some serious bullpen shenanigans

The Rays have already broken new bullpen management ground this season, what with that whole "start the game off with a reliever before bringing in your starter" idea (which has worked like gangbusters so far, by the way). On Tuesday afternoon against the Nationals, though, manager Kevin Cash took things to another level entirely.
With Tampa Bay clinging to a 1-0 lead in the top of the ninth, Cash faced a dilemma. He wanted a lefty to face lefty sluggers Bryce Harper and Juan Soto, but in between the two in the lineup sat righty Anthony Rendon -- who has a habit of mashing left-handed pitching. Rather than using two different lefty relievers and making three pitching changes, Cash just got a little creative: He brought in lefty José Alvarado to face Harper, and then, after Harper drew a walk, he called on righty Chaz Roe to face Rendon -- while Alvarado remained in the game at first base.

Regular first baseman Jake Bauers swapped gloves and headed out to left field, while left fielder Mallex Smith shifted over to right and right fielder Johnny Field came out of the game.
Naturally, Alvarado was pretty confused at first.
"[He was] pretty shocked," Cash told MLB.com's Bill Chastain after the game. "Obviously there's a language barrier. The best was Wilson Ramos looking at me like I had two heads. I said, 'Just shut up and explain it to him.' He can make fun of me later on."
Bauers had some helpful advice, though: "I told him, 'Hey, go hold him on, don't move and catch the ball if someone throws it to you.' He went for that popup pretty good. He got to the wall quick. He stuck his hand out and everything."
Roe then struck out Rendon, and everybody resumed their normal positions: Alvarado back to the mound, Bauers back to first.

Alvarado gave up consecutive singles to Soto and Daniel Murphy, loading the bases with just one out. But Cash had one more move up his sleeve: He brought in Sergio Romo (no positional shenanigans this time), who got out of the jam and sealed the win for the Rays. 
Of course, while neither Bauers nor Alvarado had ever played their new positions in the Majors before, this is hardly the first time a reliever has been asked to go above and beyond. The Astros put Tony Sipp in the outfield back in 2014, and last year Joe Girardi used reliever Bryan Mitchellas a first baseman with some of New York's bullpen unavailable.
And then there's the master of defensive manipulation himself, Joe Maddon. When he's not busy sticking Anthony Rizzo at second base, the Cubs skipper has never met a pitcher he couldn't turn into a fielder -- whether it's righty Steve Cishek and lefty Brian Duensing forming a left-field/relief platoon against the Brewers a few weeks ago or Travis Wood making the catch of his life in extra innings back in 2016: