Biddle will join the Mariners in Texas, while Vizcaino is on the 60-day injured list after undergoing surgery on his right shoulder on April 17.
The Mariners have already used 20 relievers this season and rank 27th in the Majors with a 5.45 bullpen ERA.
The 27-year-old Biddle is 0-1 with a 5.40 ERA in 15 games with the Braves this season, with his ERA jumping from 2.38 after allowing four earned runs in one-third of an inning over his last two appearances before going on the 10-day injured list with a right thigh bruise.
Biddle was activated off the injured list last Tuesday before being designated for assignment on Wednesday, following a four-game rehab assignment with Triple-A Gwinnett.
“He’s got a pretty good arm,” Mariners manager Scott Servais said. “I don’t know a ton about him other than he has a good fastball, curve and slider. Looking at the numbers, he had a pretty good year last year, was off to a rocky start this year. That’s why guys are available. Hopefully we can bring him in and get him going in the right direction again.”
Biddle went 6-2 with a 3.46 ERA and one save in 75 outings for the Braves over the past two seasons, including a 3.11 ERA in 63 2/3 innings as a rookie last year. He was a first-round Draft pick by the Philles in 2010.
Vizcaino, 28, pitched in four games this season -- going 1-0 with one save and a 2.25 ERA -- before having season-ending surgery. He’s posted a 13-11 record and a 3.01 ERA in 206 relief appearances over parts of seven seasons with the Braves and Cubs.
Swarzak was acquired by the Mariners from the Mets as part of the Robinson Cano/Edwin Diaz deal, and he was 2-2 with a 5.27 ERA in 15 outings, including 3-for-6 in save situations. He pitched well initially after coming off the injured list in early April, but he has allowed 11 runs (eight earned) with six home runs over 8 1/3 innings in his last nine outings.
Swarzak is earning $8.5 million this year, while Vizcaino is making $4.8 million and Biddle is near the MLB minimum at $575,000.
Both Swarzak and Vizcaino will be free agents next year, so Vizcaino’s inclusion in the deal is primarily to equal the money exchange. The Mariners are also sending close to $2 million to the Braves to offset Swarzak’s salary, according to MLB Network insider Ken Rosenthal.
Biddle is out of Minor League options, but he could potentially help the Mariners in the long term as he’s under team control through 2023.
Milone to start against Rangers
Veteran left-hander Tommy Milone was with the Mariners on Monday and he will be added to the roster to start Tuesday’s game against the Rangers in the rotation spot opened up by rookie Erik Swanson’s demotion to Triple-A Tacoma last week.
Milone, 32, has a career mark of 42-37 with a 4.42 ERA over 151 games (130 starts) in seven seasons with five teams. He signed a Minor League deal with the Mariners in December and he has gone 4-2 with a 3.83 ERA in nine games (eight starts) for Tacoma.
Milone will need to be added to both the 25- and 40-man rosters. He signed with Seattle knowing there’d be a chance for a promotion to the big leagues at some point this season, given Dipoto’s rebuilding plans.
“After talking to Jerry and a couple of their guys, they made it clear there would be opportunities,” Milone said. “Maybe not right out of Spring Training, but the middle of the year. And obviously, it’s proved that a lot of guys have come and gone. I was telling myself to just stay the course, continue to battle and if things go right, I’d be up here eventually.”
Milone had some good seasons with the A’s in 2012-14 and he went 9-5 with a 3.92 ERA in 24 games (23 starts) with the Twins in ’15, but he has struggled to stay in the big leagues the previous two years while splitting time between the Brewers, Mets and Nationals.
“For me it’s a matter of getting back to being consistent on a game-to-game basis,” he said. “For a few years, I just wasn’t consistent. That’s the biggest thing is going out and have the team rely on you that you can get the job done, and I’m feeling good about that right now.”