On Thursday, FOX Sports' Ken Rosenthal reported that Castro's agent, Paul Kinzer, told his client he should be prepared for any possibility. Per ESPN's Jayson Stark, other clubs were reporting that the Cubs were "aggressively trying to include Castro in any deal."
Maddon said that nothing has changed as far as Castro goes.
"What I said the other day, I meant it," Maddon said. "He was not going to be traded. I have no idea if that's going to happen. You never know -- if somebody just blows [president of baseball operations] Theo [Epstein] away, obviously you've got to do something like that. As of that particular moment, every piece of information I've received, he's not being traded."
Maddon didn't plan on worrying about Friday's pending non-waiver Trade Deadline.
"I am not going to fret it," he said. "I'll be riding my bike here in Milwaukee."
The Cubs, who entered Thursday's series opener with the Brewers third in the National League Wild Card race, were reportedly in the market for another starting pitcher. Is the bullpen good enough to get to the postseason?
"We've got to get [Rafael] Soriano right," Maddon said. "I think that would be the lynchpin among the group. The fact he'd be able to pitch at a level that he's pitched at in the past, combined with the other names, I think that would be enough."
Soriano, who signed a Minor League deal with the Cubs in June and joined the team on July 19, has appeared in five games so far, and given up four runs over 2 1/3 innings over the past three. Maddon said the veteran right-hander, who was the Rays' closer in 2010, is still trying to catch up to the rest of the league.
"I can't say he's had enough time to get his stuff together," Maddon said. "I've seen flashes of it. The consistency hasn't been there yet."
Does Maddon think the Cubs will add a player by Friday's 3 p.m. CT deadline?
"It's possible," he said. "It just depends on getting together with these other [teams]. There's the definite possibility of it. Do I think it's going to happen? I've been asked that question almost every year at Trade Deadlines, and almost every time I've been right saying, 'Probably not.'"
However, the previous years, Maddon was with Tampa Bay. Now he's with the Cubs.
"I'm going to find out Aug. 1 -- or tomorrow at 3:01," he said.