"I want to make sure it's clear that nothing is set at this point in terms of our Opening Day roster," Hahn said. "We don't have to set that until Sunday.
"At this point, we potentially have another arm in the organization who can help us at some point during the season. I wouldn't read too much into the claim, that it happened today and therefore automatically means something is going to happen come Sunday. Let's just let the next few days play out and we potentially add another nice bullpen piece."
This much is certain regarding the White Sox roster makeup, or as close to certain as it can be before Sunday. Adrian Nieto will be the backup catcher to Tyler Flowers, with Marcus Semien starting at second base and Leury Garcia serving as the utility infielder/fifth outfielder.
Second baseman Gordon Beckham and infielder Jeff Keppinger will begin the season on the disabled list, with Beckham hoping to return when he is eligible on April 5 and Keppinger basically re-starting rehab on his right shoulder. The bullpen also looks to be lined up with Nate Jones, Matt Lindstrom, Ronald Belisario, Guerra and Maikel Cleto from the right side, and Scott Downs and Donnie Veal from the left side.
That alignment means Daniel Webb, Zach Putnam and David Purcey would open at Triple-A Charlotte, with one of the three in position to claim that final bullpen slot as of Tuesday. Lindstrom's strained left oblique hasn't been a question since he returned to the mound on March 21, having given up one run in three appearances, and the White Sox have been inclined in the past to go with at least two lefties out of the 'pen.
So there doesn't look to be an opening with Guerra's addition.
Veal, Guerra and Cleto being out of options has to figure into the equation.
"So far I didn't run into anybody who potentially is in limbo and had a chance to discuss what this may mean for them or may not," said Hahn, who mentioned that manager Robin Ventura and his staff knew this Guerra move was potentially coming and how it would impact the staff.
"It throws a wrench into it. We'll discuss it today as we go," Ventura said. "We had it set. This is one of those unforeseen things that comes up, and we'll discuss it one more time."
Beckham sustained his strained left oblique while taking swings in the batting cage following a game on March 14. If he had the positive rehab day that he had Wednesday on Tuesday, he might have had a chance for Opening Day.
Instead, Beckham will stay in Arizona for extended spring camp and then play a couple of games with Double-A Birmingham before he returns.
"I've had tweaks in the past and gotten over them pretty quick. This one was definitely worse, I just didn't know how much worse," Beckham said. "It's frustrating, but I'd rather miss five games early than miss six weeks. I feel like if I rush this that's a possibility.
"Robin and Rick have reiterated to me that we can't have that. We can't have a two-month period where I'm not playing the game like we did last year. It's more important for the team and me that I get completely healthy before I come back."
Many improvements and changes have been made to the roster, but Hahn reiterated Wednesday his work is not done. It's an ongoing process that will continue well past Sunday's morning workout at U.S. Cellular Field.
"Frankly, I don't think we are ever going to feel we are done doing that until there is a parade scheduled," Hahn said. "It's a work in progress. I know that internally we had a list of items we wanted to cross off at some point.
"We've been frank all along. We have not crossed all those things off our list. By the time we get done with this original list, whether it's in a few weeks or few months or next offseason, other needs will inevitably arise in this game. We feel that we've made a lot of progress over the last 10 months, but we know we aren't done yet."