The deal, which has not been officially announced, is slated to deliver a star-studded five-player package to Toronto that includes shortstop Jose Reyes, plus pitchers Josh Johnson and Mark Buehrle.
"They've been tough on us over the years anyway," Girardi said. "It just becomes a little more difficult. But there's a long way to the start of Spring Training and Opening Day, and there's a lot of work to be done."
Girardi and former teammate and current YES Network broadcaster David Cone were at Yankee Stadium on Thursday, helping to assemble USO comfort packs for servicemen and servicewomen in the armed forces.
The Yanks won an AL-best 95 games last season, defeating the Blue Jays in 11 of 18 meetings. But with the pending deal that also sends catcher John Buck and utility man Emilio Bonifacio to Toronto, Cone believes the balance of power has shifted in the division.
"Toronto thought they were in it last year, but injuries hurt them," Cone said. "They're definitely in it now. I think they see a golden opportunity. They see the AL East is ripe for the picking. You've got to admire them for making a move and taking a shot."
Going to the Marlins are at least seven players: shortstop Yunel Escobar, right-hander Henderson Alvarez, Cuban prospect Adeiny Hechavarria, outfield prospect Jake Marisnick, pitching prospects Anthony Desclafani and Justin Nicolino, and veteran backup catcher Jeff Mathis.
Girardi acknowledges that the Blue Jays have "definitely improved" after their injury-marred 2012, but it's not as though the Yankees have ever considered the AL East one of the softer divisions.
"We've got to worry about our club and preparing for next year, so that's really what I concentrate on," Girardi said. "Obviously I'm aware of who went to Toronto, and there's some good players that went to Toronto and that's going to make them a better team, and that I will have to deal with. But that's my focus."
Complicating matters of improving the Yanks, Cone said, is that the team is being "hamstrung" by a self-imposed requirement to get below the $189 million mark for 2014 in order to take advantage of luxury tax breaks in the new Collective Bargaining Agreement.
Because of that, Cone said, "Free agents do not need to apply here, as far as right now."
"It's shaking up the free-agent market, that's for sure -- not just this year, but a couple of years; probably since '09 or '08," Cone said. "A lot of agents are out there waiting for the Yankees to get back in the game, and they're not in the game.
"It may take a couple of more years. I think most people realize this is probably a one-year thing with the Yankees so they can reset the tax rate. If they get under one year, then maybe the Yankees will be back in play again."
Girardi said that he knows general manager Brian Cashman is at work behind the scenes, and the first two orders of the club's business appear to be retaining pitchers Hiroki Kuroda and Mariano Rivera, who are both currently free agents.
Andy Pettitte is also on the Yanks' radar, and Girardi said that he recently touched base with the left-hander, who once again is weighing his desire to pitch another season against the call of retirement.
"I've spoken to Andy some," Girardi said. "He's got to make a decision, the Yankees have to make decisions. We liked the way he threw the ball last year. Obviously he missed some time with the broken leg, but we liked what he did."
Girardi said that his sense continues to be that Pettitte will pitch in 2013, but he is not ready to nudge his former teammate for an answer.
"I don't push guys yet," Girardi said. "I've always said it's got to be in their gut, what they want to do, and sometimes players one day will feel one way and another day will feel another way. Time will tell here."
The Yankees extended one-year, $13.3 million qualifying offers -- all since declined -- to Kuroda, right-hander Rafael Soriano and outfielder Nick Swisher, and also have hopes of retaining catcher Russell Martin. But Girardi said the spotlight right now needs to be on slotting capable arms behind ace CC Sabathia.
"It starts with pitching," Girardi said. "If you don't have the pitching, it's going to be hard to compete on a daily basis. Building this rotation is extremely important."