MESA, Ariz. -- Santiago Casilla's much-anticipated reunion with the A's unfolded on Sunday morning, with the veteran relief pitcher finally arriving in camp after waiting out a lengthy visa process in the Dominican Republic.
Casilla, who had been keeping up with a throwing program at the team's academy in his homeland, completed a bullpen session less than two hours after his arrival. Asked when he thinks he'll be ready to pitch in a game, the 36-year-old flashed his warm smile and said, "All I need is a ball in my hand."
A's manager Bob Melvin wasn't yet ready to map out Casilla's game schedule, though, and held off announcing a date for his Cactus League debut.
"We're just kind of getting a handle on where he's at, how much throwing he's done and kind of where we proceed with him," Melvin said. "I just want to see how he feels each and every time."
Nearly eight years removed from his last appearance in an A's uniform, Casilla found one waiting at his locker, after parading through a line of familiar clubhouse workers eager to welcome him back.
"This is something special," Casilla said through interpreter Juan Dorado. "It was the first uniform I put on when I signed out of the Dominican, and it was also the first uniform I put on when I came over to the [United] States, so it means a lot to me."
Casilla, who amassed 123 saves and a 2.42 ERA in seven seasons with the Giants following his departure from Oakland, has plenty of catching up to do with the A's. Accordingly, he decided to bypass the first round of the World Baseball Classic, which begins this week.

Casilla has not yet ruled out participating in the second round, though.
"I want to get ready for camp," Casilla said. "That's the most important thing for me. Obviously, I'm very disappointed backing out [of the tournament for now]. But I think [the Dominican team understands] I have to get ready for the season."
Casilla's arrival prompted further discussion about his role with the A's, who have an abundance of closing options. Ryan Madson handled the job on most days in 2016, and Sean Doolittle and John Axford also have experience as closers, making for an intriguing decision when camp breaks.
Melvin has left open the possibility of entering the regular season with more than one closer. Casilla, he said, is definitely in the mix -- despite tying for a Major League-leading nine blown saves in 2016. Madson had seven.
"You know what, there are a lot of guys that have had some blown saves," Melvin said. "When you're that good and have had the success that he's had, it stands out a little bit. But it's not like we were perfect here.
"It could be anybody, and Ryan Madson certainly didn't do anything that would suggest he's not the closer. But we have a different complement of guys now, especially with Santiago. Right now, all these guys are just about getting ready for the season, and they've all stated to me they're open to just about anything. They just want to win."
"I know what kind of pitcher I am and I know what I need to do," said Casilla. "... I'm just happy to be here with the A's. I feel like they have a ... need for me here."