Seattle now has 10 days to trade, release or outright Bonderman to the Minors.
Manager Eric Wedge said the club will promote a player from Triple-A Tacoma to take Bonderman's spot in the rotation, though that move won't be announced until later in the week. For now, Luetge provides an extra arm in the bullpen.
The logical replacement from Tacoma figures to be Erasmo Ramirez, who has gone 3-3 with a 3.09 ERA in seven starts since returning from an elbow problem in early June.
Ramirez, 23, was contending for a rotation spot this spring before his elbow issue arose late in camp. The Nicaragua native was 1-3 with a 3.36 ERA in 16 games (eight starts) last year for Seattle and figures to be part of the club's future if he can stay healthy.
Bonderman, 30, went 1-3 with a 4.93 ERA in seven starts after returning to the Majors on June 2 for the first time since 2010 with the Tigers. Bonderman got roughed up in his debut, then pitched well in a four-start stretch from June 7-23, when he was 1-0 with a 1.42 ERA in 25 1/3 innings. But he was 0-2 with a 10.80 ERA in his last two starts, allowing 13 hits with seven walks and 10 earned runs in 8 1/3 innings against the Cubs and Reds.
Wedge said Bonderman's last two starts were not the main reason for his departure, however.
"It's really more about who is coming versus that," the skipper said. "When you talk about Bondo, you have to really appreciate his effort and what he's done to get back to where he is. But we still feel there's some more work to do there. Again, it's more about who we're bringing up than anything."
Bonderman went 2-4 with a 4.52 ERA in 11 starts with Tacoma to start the year after agreeing to a Minor League deal prior to Spring Training that required the club to release him by June 1 if he didn't earn a promotion. The club brought him up at that time, but has decided now to go another direction after what turned out to be a seven-game trial run.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.