PAWTUCKET — At first glance, the numbers don't add up. In Boston, the starting rotation has a 5.40 ERA. Brad Penny, the fifth starter, has a 6.07 ERA, though he has given Boston just enough to win on many nights.

In Pawtucket, two prime options bide their time in relative obscurity. Clay Buchholz, who has a 1.60 ERA, has been dominating hitters. Michael Bowden's 0.86 ERA is tops in the International League, and both young pitchers have looked every bit as good as those numbers suggest. Buchholz, 24, clearly has major-league stuff, and Bowden, 22, has impressed during his two major-league appearances over the last two seasons.

So why have the Red Sox not called up one of these highly touted hurlers? It seems like neither one has much left to prove at Triple A.

Maybe it's because their value will never be higher than it is right now in the minor leagues.

With speculation mounting that the Red Sox would like another hitter to bolster the lineup, or possibly to step in for the slumping David Ortiz, the names Bowden and Buchholz are being bandied around more than ever.

One of them, it would seem, would be a significant part of any package deal, one that could bring back, for instance, Cleveland's Victor Martinez.

If they are called up and flame out, then that value could drop off. Buchholz has already had one problem season at the big-league level, struggling badly in 2008 after wowing fans in his brief 2007 introduction. If he comes up again and has difficulty, other teams could worry that he is never going to make the leap and dominate at the major-league level. Bowden, similarly, is no sure thing in the majors. His specialty is control, and there is some concern that he might run into trouble trying to finesse major-league batters.

At the same time, Boston already has reinforcements coming. John Smoltz made his first rehab start for the Class-A Greenville Drive Thursday, and he could be back by mid-June. The Boston rotation will be crowded enough with the re-introduction of a Hall of Famer. Bringing up the young aces would further complicate matters.

Buchholz has heard every explanation under the sun as to why he hasn't been up yet –– and every trade rumor, too. He knows there's nothing he can do but keep shutting down the opposition. Either that will eventually force Boston to call him up or it will drive up his value enough that another team will want him badly enough to pay a steep price.

"You hear people talk about it. But the position I'm in now, where it feels like I'm pitching well enough to pitch for the big-league club, whenever somebody says something about me being traded, if it's a package deal for me and Mike, then they're expecting us to go in and help that other team, too," Buchholz said.

When trade rumors first started dogging him, about three years ago, he paid attention to every one. It was hard not to. Several years ago, he and Bowden were both mentioned as part of a potential trade for the White Sox' Mark Buerhle, and the two talked about the positives and negatives. But that never happened, just like a dozen others.

Listening to them can be cause too many highs and lows, so Buchholz has done his best to shut them out. But it's not always easy.

"I feel like I can help a big-league club, regardless of who it is. But you hear it; it's hard not to hear it sometimes. People are calling up, from where you're from, asking, hey, are you going to get traded tomorrow?"

Such is life for Buchholz and Bowden, potential trade chips, Triple-A aces and fodder for baseball's version of the gossip column.

"It's good on some parts, and on other parts it's not, because of how many times it has been mentioned, me getting traded, and none of it ever happening. I'm still here in Triple A," Buchholz said.

dbarbari@projo.com