The most controversial batting instructor in the major leagues was due to arrive in Jupiter late Tuesday and could be on the field as early as Wednesday, the date for pitchers and catchers to report for St. Louis.
Several of his pupils are already here, including second baseman Skip Schumaker, who is among a handful of Cardinals familiar with McGwire's passion for hitting after offseason workouts in California. He's perhaps McGwire's biggest booster on the team, having worked with the slugger he grew up idolizing since 2005.
The leadoff hitter had one complaint: No longer will he have McGwire's undivided attention.
"I'm excited about it," Schumaker said. "I'm not excited I have to share him. He's helped me a whole lot the last couple of years and I'm excited to have him for a full season."
Last month, McGwire ended more than a decade of denials and evasion by admitting that he used steroids and human growth hormone as he became a home run king. Schumaker said teammates will quickly learn that McGwire, though tarred and feathered by many as a poster boy for performance-enhancing drugs and thus far locked out of the Hall of Fame despite his 583 homers, has plenty to offer.
"He preaches consistency and not to have a roller-coaster type of year, and to know your swing," Schumaker said. "He's convinced me I know my swing and he's always been super positive."
As early arrivals to camp dodged boxes during the unpacking process from the move south, no one seemed too concerned that a media circus was coming to Roger Dean Stadium, the Cardinals' spring home. Cardinals spokesman Brian Bartow did not expect a crush of national media for the official camp opening, even if McGwire suiting up appears to be the biggest story at the outset.
"I'm sure there'll be a lot of stuff going on early, but hopefully that'll all move aside," pitcher Kyle Lohse said. "I've heard a lot of good things about him and hopefully everybody will get their work done in peace."
Big Mac's return to baseball comes just over a month after admitting to steroids use during his dramatic power surge in the 1990s, including his then-record 70-homer season in '98. Whether his confession went far enough is an open question.
In January, the Cardinals were optimistic that McGwire would be able to fully focus on his coaching debut after he submitted to a round of interviews and made two brief appearances in St. Louis. Manager Tony La Russa went beyond optimism, basically warning that McGwire would have plenty on his plate without revisiting his flawed career.
"He has been more forthcoming than anybody yet," La Russa said. "What more else is there to say? This is definitely go-forward time."
Bench coach Joe Pettini said simply: "I hope we don't have to put him on display."
Undoubtedly, there will be more questions when the 46-year-old McGwire shows up. His assertion that steroids allowed him to heal from injuries but did not offer a power boost was bothersome to many, with even general manager John Mozeliak weighing in against that notion.
Until the hubbub dies down, the clubhouse and the field will be McGwire's sanctuary. He figures to get a royal reception from players who won't judge him for any misdeeds from the past.
Several pointed out that during McGwire's heyday, pitchers had equal access to steroids.
"I'm happy I wasn't playing in that era so I didn't have to even think about it," said Joe Mather, a candidate for the Cardinals' vacant third base job. "But you can't really go back and judge somebody when you were never really there."
Growing up, Mather always wore McGwire's number.
"He was my guy," Mather said. "I'm looking forward to it, that's for sure. All I've heard is good things."
Schumaker has vivid memories of watching Cardinals games during the 1998 season when McGwire broke Roger Maris' single-season home run record during a dramatic race with Sammy Sosa, helping wipe away the lingering memories of the strike that wiped out the 1994 World Series. Looking back, he does not feel cheated.
"It was a great time for baseball and he brought baseball back," Schumaker said. "Nothing is tarnished for me. We have confidence in him, he's our hitting coach and we're excited to work with him."