Niemann picked up the win in his first Major League start, April 13 against the Orioles, then he took the loss Friday night against the White Sox. Johnson has not yet arrived, but a move had to be made Sunday, and Niemann turned out to be the guy.
"I knew that was a possibility," said Niemann, who posted a 5.79 ERA. "[There are] a lot of guys here, and that's just how it works."
Several other moves are yet to be made. Catcher Dioner Navarro is expected to be activated from the disabled list prior to Tuesday's game, which means one of the backup backstops will need to return to Durham.
"Navvy has to play tomorrow night, and we'll see how he comes through that before we make our final move Tuesday," Rays manager Joe Maddon said.
In other rehab news, Matt Garza has been tabbed to be the Rays' starter on Friday against the Red Sox. Garza pitched 3 2/3 innings in a start for Class A Vero Beach on Sunday. Since a pitcher was sent down Sunday to make room for a position player, a position player will be sent out Friday to make room for Garza.
Niemann would have pitched Thursday. Now, Andy Sonnanstine will move up from Friday to fill that slot.
"I'm going to take away a wealth of information from the seven days I've been up here," Niemann said. "[I'm going to] go back and really put that to use."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.