Both moves were anticipated. Grilli concluded his rehab from the strained left oblique that had landed him on the DL on April 26 with back-to-back simulated games Tuesday and Wednesday. Sanchez knew his fate when veteran catcher Russell Martin came off the DL on Thursday.
Before Friday's game against the Nationals, it seemed unlikely Grilli would be put in a high-leverage situation.
"I doubt under any circumstances Jason would get the ball in the ninth to close. I don't think that would be fair to him," manager Clint Hurdle said. "We'll give him the ball [in lower-pressure situations] a couple of times, and evaluate him after each time."
Grilli got a similar treatment last season, upon returning from a six-week absence with a forearm strain. He made two low-leverage appearances before returning to the end-of-the-relief line.
However, Mark Melancon was unavailable Friday night after needing 23 pitches to close out Thursday's 3-1 win over Washington, so Grilli had to get the call as closer.
The right-hander walked one, struck out one and got a big assist from Josh Harrison, who made a leaping catch to record the final out of the 4-3 victory.
Russell Martin remained "out" Thursday night as he served a one-game suspension, but he was in the Friday lineup, backed by another veteran, Chris Stewart.
Previously already earmarked to take over as the Bucs' No. 1 catcher in 2015, Sanchez solidified those prospects by batting .278 in 21 games, 19 of them starts, with 12 RBIs.
"Tony got great experience while he was here," Hurdle said. "He's been able to develop. He's done a very admirable, professional job while he's been here."
Grilli went on the DL soon after consecutive blown saves on April 19-20 against the Brewers. Prior to that, he had converted four straight saves.
While the fill-in closer, Melancon was successful on eight of 10 save opportunities.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.