Sherrill, 34, has been dealing with elbow soreness since the start of Spring Training in early February. He has struggled in two regular-season appearances, allowing four earned runs and six hits in 1 1/3 innings with one walk.
The Mariners listed his injury as a strained flexor bundle in his elbow. His DL stint is retroactive to April 10.
"George has been struggling a little physically and having trouble getting over the hump. So we're going to get him looked at today and put him on the DL," manager Eric Wedge said. "Charlie was the next guy up. He did everything he could to make this team to begin with, but we just weren't able to make it work numbers-wise. So we've got him back up here."
Furbush, 26, was in uniform and available for Friday's home opener against the A's. The left-hander made the trip to Japan with the Mariners, but didn't pitch in either of the two opening games in Tokyo and then was optioned to Tacoma on April 4, when the Mariners reset their 25-man roster.
Furbush, acquired in the Doug Fister trade from the Tigers last July, has pitched two games in Tacoma this spring with no runs and one hit with six strikeouts in four innings.
"I had a good time in Tacoma," said Furbush. "But I'm happy to be back here for Opening Day. This is great. I just tried to do the best I could there and try to get back here as soon as I could, and this is probably a little quicker than I thought, for sure."
Furbush worked as a starting pitcher in the final two months last year for Seattle, but has been used strictly in relief this spring.