Now, in the aftermath of Clemens' return, the next big mystery to be solved is this: How good can Clemens, soon to be 45 years old and returning to the more hitter-friendly American League, really be for the Yankees?
"That's the big question that everybody wants to know," Pettitte said. "I think any time that anybody tries to doubt what he can do, he proves everybody wrong.
"It's hard for me to sit here and say that he's not going to be successful or that he's not going to have success because I've been able to watch him pitch. He looks to me like his command is better than it's ever been."
Yankees manager Joe Torre echoed similar thoughts concerning Clemens, who was 7-6 with a 2.30 ERA in 19 starts for the Astros in 2006.
Regardless of Clemens' spoken intentions to perform just as he did while serving as a 25-year-old fireballer for the Red Sox, the Yankees' demands of Clemens are for him to compete competently.
"What we can expect from Roger, and it's reasonable, is that he gives us a chance to win," Torre said. "Does that mean he's going to strike out 12 and pitch seven innings? Not necessarily. But I think when you send him out to the mound, and whether it's five or six innings, he's going to give you a chance."
Pettitte said he spoke to Clemens after the formalities on Sunday afternoon, which included Clemens following up on his introductory press conference by promptly bringing pitching coach Ron Guidry out to throw a bullpen in the empty Yankee Stadium.
Some things never change. Same old Rocket.
"It's obviously exciting," Pettitte said. "Anytime you add him to a team, it's going to be a huge lift. I think everybody's extremely excited to have him back."
The clocks have started on Clemens' progression to the mound in New York. Major League Baseball rules do not allow players to work out with other team's Minor League affiliates, which means Clemens could not use the Astros' Minor League facilities in Lexington, Ky., as he did last season when he was en route to the big-league team in Houston, Clemens has instead decided to begin working out at the University of Kentucky complex.
No specific dates have been established yet, but Clemens -- who remained in the New York area on Monday for a golf tournament -- is clearly set to prepare his body for big-league duty.
Until then, Clemens' old locker will remain vacant, having been cleared of all items -- optioned reliever Colter Bean was its previous inhabitant -- and adorned with the same nameplate he used during past seasons in the Bronx.
"As long as he can stay healthy, I think he can do a great job for us," Pettitte said. "I don't think we're expecting him to throw eight or nine innings, but he's going to give us quality starts every time out."
The family plan: One season ago, as general manager Brian Cashman recalls, the Yankees were the only team involved in a Clemens pursuit to steadfastly reject the idea of the right-hander's so-called "family plan," where Clemens would have the option to leave the club for certain games.
The Astros, Rangers and Red Sox, Cashman said, all agreed to allow Clemens those certain contractual privileges. It ended up hurting the Yankees, as Clemens decided to sign a one-year contract with the Astros in late May.
As a result, Cashman said the Yankees conducted internal discussions to decide how best to handle the "family plan," should a situation arise again when they would be involved in a Clemens sweepstakes.
Talks began in December, involving Cashman, Torre, coaches, players, plus principal owner George Steinbrenner and other front office officials. The GM said that it was decided that the Yankees would indeed have interest in a second tour of duty from Clemens and that -- unlike in 2006 -- the Yankees would sign off on the "family plan."
"It's something that's unique," Cashman said. "It's not something we personally came up with, but obviously it's something that we've committed to and we had to commit to. We'll see how it plays out, but without a doubt, we will honor that."
Torre said that he met with select players in Spring Training to discuss the ramifications of Clemens' special privileges. He said that he is unconcerned that some players may deem it unfair or unequal, but acknowledged that if a problem arises, the Yankees will address it.
In the meantime, Torre said he was not inclined to worry about the possibility of a clubhouse rift that may or may not occur.
"We don't know what's going to happen," Torre said. "Just because it's a part of his contract, we don't know what's going to happen or how it's going to happen. We haven't gone on a schedule. We'll take it and see where we are and see what comes of it."
Stay a while: Darrell Rasner knew when he took the mound on Sunday afternoon that there was an extremely good chance he'd be packing his bags for Triple-A Scranton/Wilkes-Barre, called up simply for a one-and-done start against the Mariners.
So when Rasner hurled 5 2/3 scoreless innings against Seattle, changing the Yankees' thinking and prompting them to demote ineffective starter Kei Igawa instead, the right-hander wondered what had happened.
He'll remain in the rotation for now, scheduled to make his fifth start of the season Friday at Seattle. The assignment is fine by him, but it wasn't something he'd even deemed possible.
"I didn't think that far," Rasner said. "I was just thinking to go out there and help this team [on Sunday]. I have no control over that."
Minor matters: Brett Smith, a right-hander for Double-A Trenton, has been named the Eastern League's Pitcher of the Week for the week ending May 6th. Smith, 23, made two starts for Trenton last week and went 2-0 with nine strikeouts and a 0.00 ERA.
A second-round draft selection in 2004 from UC Irvine, Smith is second in the Eastern League with an 0.92 ERA and has not given up a run in his last 27 1/3 innings.
Coming up: The Yankees welcome the Texas Rangers to Yankee Stadium on Tuesday, sending left-hander Andy Pettitte (1-1, 3.00 ERA) to the mound. The Rangers counter with right-hander Mike Wood (0-0, 3.12 ERA), with first pitch set for 7:05 p.m. ET on YES.