"This team was put together really well," Gregerson said.
The bullpen might be general manager Billy Beane's best construction this past winter.
Closer Jim Johnson and Gregerson were acquired in trades on the same day. Lefty Fernando Abad also was brought in via trade, and Eric O'Flaherty was signed to a two-year deal coming off Tommy John surgery, which will keep him out until the middle of the season.
"Ever since I was traded, I took notice of the moves they made, and it was obvious what they were trying to do," said Gregerson, who will be a free agent after the season. "It will make all of our jobs easier with the guys they added. We have a lot of guys who all have experience in pressure situations, a lot of guys who are able to do that job at any time.
"A lot of people are excited about, not just the bullpen, but the makeup of the team in general. ... Everyone here is here to win."
Gregerson, 29, was 6-8 with four saves and a 2.71 ERA in a team-high 73 games a year ago for the Padres, and he figures to handle the eighth inning for the A's, ahead of Johnson. But with such depth from returners Ryan Cook, Dan Otero and lefty Sean Doolittle, specific roles may go undefined.
"In San Diego, we ran it one way -- sixth, seventh, eighth, ninth inning, had guys for those roles, and a lefty specialist for that role. With the guys we have here, I assume we'll all get in at different times," Gregerson said. "With the guys we have here, I think it would be in a weird platoon role, I guess, of setup men. Which to me means maybe you don't have to be burned three days in a row or four days in a row.
"To have five or six guys who can all set up and close, it's pretty special. I really don't know what the plan is. I can only speculate. Either way, I think it's going to work."
Despite the lack of defined roles at this time -- nearly three weeks still remain in Spring Training -- Gregerson, who spent three years in the Cardinals system before he was traded to the Padres, is enjoying the overall atmosphere in his new clubhouse in addition to the bullpen's depth.
"It's nice to know you always have someone behind you to back you up if you need it or be able to back up someone else if they need it," he said. "You know you have a guy coming in who is very capable for that job. Everyone has their own personalities, but we all get along.
"A lot of people have asked how camp is going with a new team, but once you start talking to people it's all baseball. And it's all about how each one of us can help the team win."