The Rays had to clear room for Gross on the 25-man Major League roster after acquiring Gross in a trade with the Brewers on Tuesday, and they decided designating Johnson made the most sense, even though they just claimed him off waivers from Oakland on Friday.
"Obviously it's a little bit of an awkward situation," said Andrew Friedman, the Rays' executive vice president of baseball operations. "We have a tremendous amount of respect for Dan as a player. It was something for us, a lot of variables changed from Friday until today. Obviously at the time we claimed him, we weren't sure about Carlos [Pena's] hamstring, and we weren't sure about how quickly he would be able to get back. And we didn't think this trade would happen at that time."
Though the situation is awkward, Friedman said a lot of information changed from when they claimed Johnson, and he said that everything the Rays did was "on the up and up."
"When we claimed him on Friday, we didn't know what we know now on a couple of different fronts," Friedman said. "Again, we have a tremendous amount of respect for him as a player and we were anxious to see how he would perform for us. But the way things broke, and the trade we were able to make, it didn't really fit for us from now through the next couple of weeks."
Also factoring into the decision was the fact Cliff Floyd's knee is reported to be doing better. Floyd went on the 15-day disabled list on April 9 to have right knee surgery.
"It would have been hard for us to find Dan playing time; we could have carried him a little longer, but it would have been hard to find him playing time," Friedman said. "We feel like this was the right move to let him try and get an opportunity to go play somewhere regularly."
Friedman said Johnson was "professional about it" when he told him he had been designated.
"I think he understood the situation, and was a pro," Friedman said.
Rays manager Joe Maddon said "it was unfortunate the way it came down."
"I felt awful about the whole scenario," Maddon said. "Andrew spoke first, I spoke second and it was a tough moment for him."
Friedman did not rule out Johnson going to Triple-A Durham to play, but he said, "I'd be surprised if someone didn't claim him and give him a chance to play a little bit."
Meanwhile, Gross arrived at the Rays' clubhouse shortly before game time Wednesday.
"It's been a little bit of a whirlwind [day]," Gross said. "But I'm happy to be here. ... I think this is a great group of guys they've got here. I'm looking forward to being a part of it."
Friedman said he thinks Gross will "get a fair amount of playing time," adding that just how much would be dictated by performance.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.