It's already been tried quite a bit. Well, some. Joe Maddon did it against us last year, for one. Yeah, they did it with Duensing and Cishek. Cishek started the inning, but went to left-field while Duensing came in to face Thames. Then they switched as Cishek came back to the mound to face Cain. After that Duensing came back in from LF to pitch to Yelich. The Brewers apparently did it once under the reign of Tom Trebelhorn with Chuck Crim and Tony Fossass (LINK). In that instance Chuck Crim went to 1B for one batter. It would be interesting to do this with the pitcher going to first base. Not that they are great defenders, but you could move Thames/Aguilar around if you wanted to keep their bat in the lineup.