Much has been made about how the Reds' outfield has morphed over the past two years. Austin Kearns has established himself in right field. Adam Dunn, his second-half slump notwithstanding, is a budding star in left. And Ken Griffey Jr. -- remember him? -- remains GM Jim Bowden's shadow and occasional center fielder.

Then there's Wily Mo Pena.

You might never have heard of Wily Mo Pena, but he's in Cincinnati, and not going anywhere. Literally. He is one of baseball's most promising power prospects. He also is just 20 and considers the strike zone roughly the size of a small hotel. A perfect candidate for two full seasons at Double- and Triple-A. But he won't get them.

	Wily Mo Pena is congratulated after hitting his first career home run in the major leagues on Sept. 12.

Called up by the Reds last week, Pena is one of a handful of prospects who, upon turning professional, demanded and received major-league contracts that forced them to move up the ladder so fast that their development could very well be compromised. The $3.7 million deal Pena signed with the Yankees in April 1999 started the clock ticking -- major-league rules gave him just four seasons in which he could be optioned to the minor leagues without being exposed to waivers. Those options are now up. He almost certainly has played his last minor-league game, readiness be damned.

"His tools are almost off the chart ... at the Hall of Fame, great, great player level," Reds manager Bob Boone raved earlier this year. "But he's got a lot of learning about baseball to do."

Jumping from low Class A to Double-A Chattanooga this year to accelerate that learning process, Pena hit just .255 with 11 home runs and 47 RBI, due in part to some early hamstring problems. He walked just 36 times while striking out 126 times, often flailing badly against out-of-the-zone breaking pitches. There is no doubt he has no business playing at the major-league level.

Yet he will. The Reds, unless they can trade the chore of weaning Pena to another club, will have to keep this 6-foot-3, 220-pound moose of a kid on the major-league roster next year or almost certainly lose him to waivers. He will have to learn to hit in the big leagues -- which is difficult to do while the real major leaguers actually play.

Cincinnati doesn't look to be the best place for a young outfielder to need playing time. Barring injuries the outfield should be Dunn, Griffey and Kearns, with Sean Casey at first base and no DH. There have been rumblings of the Reds' moving Dunn to first and trading Casey, who struggled with shoulder problems this year and hit just .261-6-42, but after his major shoulder surgery -- from which he is expected to recover by spring training, though it's hard to know the long-term effects -- that will be difficult.

The bench is cluttered, too, with Reggie Taylor and Jose Guillen pushing each other -- in more than the conventional ways -- as well as perennial prospect Ruben Mateo. (Juan Encarnacion was dealt to Florida this summer to somewhat ease the outfield glut.) Pena will most likely be treated much like a Rule 5 draft pick and used on the 25-man roster primarily in pinch-hitting, pinch-running and defensive situations.

	“	His tools are almost off the chart ... at the Hall of Fame, great, great player level. But he's got a lot of learning about baseball to do. ”
		— Bob Boone, Reds manager, on rookie Wily Mo Pena

Pena singled in his first big league at-bat against the Pirates on Sept. 10, encouragingly taking two outside breaking pitches that Boone expected him to chase, and then two days later hit a solo homer in his first big-league start (in left field) against the Cubs. That game also featured a fine running catch by Pena that demonstrated his fine speed and defensive skills that could allow him to play center. But he has played only sporadically since, often pinch-hitting, and stands 3-for-9 with four strikeouts in seven games.

Boone is viewing these last two weeks as a chance for Pena to dip his toes in the big leagues before being pushed into the pool next year: "Just being around will help him so that he won't be in awe of it all," he said. "It won't be a fair judgment of him, but we can see how far behind or how far ahead he is and see what we have to work on next spring."

Asked whether Pena should be in the majors next year, Boone said, "You'd like not to have the added pressure. When you're ready to play in the big leagues, you play in the big leagues. That's my position on that. But it is what it is."

Pena isn't the only minor leaguer operating under this time pressure, and for some it winds up more benign than others. Mark Prior signed a major-league deal after being drafted No. 2 overall by the Cubs in June 2001 and was pitching in the big leagues within a year. Rangers slugger Mark Teixeira should reach Arlington next season, long before his 2005 deadline. But several other prospects -- Padres first baseman Xavier Nady (deadline 2004), Reds catcher Dane Sardinha (2004), Devil Rays shortstop Jace Brewer (2004) -- could be forced to stick in the big leagues before they're ready.

The Yankees gave Pena his time bomb of a contract after he became one of the hotter international prospects in 1999; the Mets had signed him the previous year, but the deal was later voided because Major League Baseball questioned the authenticity of his father's signature. Mark Newman, head of the Yankees' player-development operation, had little doubt he would make it to the majors after the four seasons. "We'd studied the top Latin outfielders, guys like Sammy Sosa and Juan Gonzalez, and the lion's share made it in that time frame," Newman said. Sosa, a player to whom Pena has often been compared, had a 123-21 strikeout-walk ratio in Class A ball in 1987 but later learned the strike zone enough to be a productive major-league player, later a superstar.

But the Yankees dealt Pena to the Reds to re-acquire Drew Henson last March, leaving him two seasons to develop for Cincinnati. Pena, a Dominican still very uncomfortable with English, said he considered the ticking clock no hindrance to his development. "I don't have pressure because all the time I knew that I would play in the majors," he said. "I knew I would work hard enough to make it."

He has made it, all right. Ready or not.

Alan Schwarz is the Senior Writer of Baseball America magazine and a regular contributor to ESPN.com.