"Kevin Towers earned a reputation of being a gunslinger in his years as general manager of the Padres, and he's taken that approach with him to the D-backs. And now he's open for business.

No player on the current D-backs roster is untouchable, and in recent days at this week's General Managers Meetings, he has been judging interest from other clubs in right fielder Justin Upton and shortstop Stephen Drew, among others. The Yankees and Red Sox reportedly have emerged as suitors for Upton.

"All the years I was in San Diego, Trevor Hoffman had a no-trade clause and I still listened to interest in him," Towers said. "We're in the information business. You never know when a team wants to grossly overpay because they think they're one player away. You need to listen. If the right deal presents itself, I want to be prepared and ready."

About interest in Upton, in particular, Towers added: "Right now it's just people kicking the tires. Not with just him, but with several of our players. Nothing is imminent or close."

Last spring, the D-backs inked Upton to a six-year, $52.25 million contract, in which his salary is scheduled to jump from $500,000 to $4.25 million in 2011. Towers is committed to rebuilding the bullpen and adding a closer, and the latter he said would more than likely come via a trade rather than the free-agent market. He'd also like another starting pitcher, a left fielder and more bench strength.

The D-backs are also committed to cutting the player payroll from $75.5 million at the start of this past season to about $60 million in 2011. It's no wonder that Towers is listening to offers.

Upton, at 23, is a five-tool player with oodles of potential, but he struck out 152 times in 133 games as all of his offensive numbers tumbled from 2009. The team whiffed a record 1,529 times and lost 97 games to finish last in the National League West for the second consecutive season.

Upton played only four times after Aug. 30 because of an ongoing left shoulder injury that he hurt taking a swing at the plate. "