Rodriguez played in his final extended spring game Thursday morning, finishing 0-for-2 with two walks and playing three innings in the field. Feeling no pain after the game, Rodriguez consulted with Girardi and general manager Brian Cashman before making his decision.
"There was a buzz in his voice," Girardi said.
And a buzz in the clubhouse, once a floundering offense learned that it was about to receive a major jolt. Rodriguez has led the Yankees in home runs and RBIs in each of the past four seasons, and he ranks 12th all-time with 553 career home runs. Only one active player, his former Mariners teammate Ken Griffey Jr., has more.
Rodriguez has hit at least 35 home runs and driven in at least 103 runs every year since joining the Yankees in 2004.
"He's definitely one of the best players around," left fielder Johnny Damon said. "It will give us some confidence."
It will also provide protection for No. 3 hitter Mark Teixeira, who has spent most of his first season in pinstripes mired in one of the worst slumps of his career.
"It's going to be huge," Teixeira said. "We've done a decent job of picking up the slack ... but you just can't replace Alex. No matter how hard you try, no matter how hard everyone tries to step up, you just can't replace him. So it will be great to have him back."
The assumption, shared by nearly every Yankee, is that Rodriguez won't have much trouble regaining the form that helped him earn a reputation as one of the game's most feared sluggers. But questions remain. Rodriguez is coming off major surgery, and at one point was considering an operation that would have kept him sidelined for perhaps all of this season.
He will also be playing in his first Major League game since a February news conference in which he admitted to using steroids from 2001-03 with the Rangers, and is certain to receive an icy reception at Oriole Park at Camden Yards.
Regardless, the Yankees expect their third baseman to quickly regain his old form.
"Alex is going to put up Alex-type numbers in the five months that he's here," Girardi said.
Certainly, Girardi will take precautions, with daily plans to check on Rodriguez's status and availability. But given A-Rod's extensive rehab in Tampa, Fla., and the fact that the Yankees have an off-day Monday, Girardi doesn't envision having to ease his third baseman back into the lineup.
"If he needs to take a day, he takes a day," Girardi said. "And it might be something where we tell him to take a day. We'll try to be smart about it."
Rodriguez has dominated headlines since a Sports Illustrated story in early February revealed that he had tested positive for performance-enhancing substances back in 2003. He later admitted to using a drug called "boli" from 2001-03 with the Rangers.
Yet a book released Monday by the same Sports Illustrated writer, Selena Roberts, charges that Rodriguez may have used PEDs as far back as high school, and as recently as during his stint with the Yankees. The book also alleges that Rodriguez tipped pitches to opposing middle infielders during his time with the Rangers, in the hope that they would reciprocate the action.
Rodriguez has not publicly responded to any of those claims.
Instead, he has spent the past week brushing aside media at the team's Minor League complex in Tampa, progressing from batting practice to glove work to sliding -- the final step in his rehab. Having accomplished all of those goals without a setback, Rodriguez managed to return earlier than the Yankees' original May 15 target date.
He will join a team desperately in need of his bat. The Yankees entered Thursday's play having averaged just 3.5 runs per game over their past four games. Despite ranking fifth in the American League in runs per game, third in home runs and fifth in batting average, the Yankees also ranked 12th in the league with runners in scoring position.
Their hope is that Rodriguez can transform that statistic.
"He's A-Rod," Teixeira said. "He's going to put up MVP numbers every single year. He's always a threat to change the game with one swing, so we're looking forward to having that back in the lineup."