The move became official Saturday once it received approval from the Commissioner's Office, which was necessary due to the amount of money changing hands.
Then, after agreeing in principle on the Snyder deal, the D-backs traded former closer Chad Qualls to the Rays for a player to be named later. No money changed hands in that deal, so it went through at that time. Qualls was informed of the move late Friday night when he was, coincidentally, with Snyder.
Church and Crosby were both signed as free agents during the offseason. Church, who was hitting just .182 at the time of the trade, signed for $1.5 million and has one more year of arbitration eligibility remaining. Crosby, batting .224, has a $1 million deal and can be a free agent at the end of this year.
"What they bring us is some veteran knowhow on the bench," interim general manager Jerry Dipoto said. "I don't think either would tell you they're having their best year in the big leagues, but just like Chad, a change of scenery should help."
Carrasco, who pitched in the D-backs' organization before, was used in long relief by the Pirates and compiled a 3.88 ERA in 55 2/3 innings. He made $950,000 -- with another $300,000 in possible incentives -- and can be controlled by the D-backs through 2012.
"We've had him before, we know the makeup is really good," Dipoto said. "He's just a versatile guy who can throw from a number of different angles."
Snyder will earn $5.75 million next season with a club option for 2012 worth $6.75 million and a $750,000 buyout.
"I think Chris was in need of a change of scenery, primarily because he wanted to play," Dipoto said.
The D-backs have until the end of the Minor League season at the beginning of September to choose the player to be named later from a list the two teams have agreed upon.
"Now we just need to pick the player we feel best suits us," Dipoto said.
Arizona actively shopped Qualls, who began the year as the team's closer, but has struggled to find any consistency and is 1-4 with an 8.51 ERA in 42 games. The right-hander, who is making $4.185 million this year, will be eligible for free agency at the end of the season.
The D-backs acquired Qualls, along with Juan Gutierrez and Chris Burke, from the Astros in December 2007 in a deal that sent Jose Valverde to Houston.
"He had a rough year," Dipoto said. "He was very thankful for his time here and he was very apologetic for the kind of year that he had. I thought he handled things very professionally. I think he was in a situation where a change of scenery will do him a lot of good."
Carrasco joined the team Saturday night and Crosby will do so Sunday, while Church will meet the team in Phoenix on Monday.