Billy Wagner thought about using his no-trade clause to torpedo a deal to the Red Sox. He agreed to go to Boston only when the new team put in writing that it would decline an $8 million option for the 2010 season.

In 2003, Curt Schilling used his negotiating hammer to get a two-year, $25.5 million extension for the Sox (which became a three-year, $40.5 million deal once Boston won the World Series).

In ’07, Eric Gagne put Boston on his no-trade list, even though it was a city where he wanted to play. The reliever did so as a means of gaining leverage over a club that he believed might want to acquire him, and saw the strategy pay off when the Sox and Rangers agreed to pay out $2.5 million that had represented potential earnings through performance bonuses.

In 2008, Padres outfielder Brian Giles used his no-trade power to blow up a potential deal to the Sox.

There is an obvious common theme. Players with no-trade clauses in their contracts have a form of leverage that they can – and often do – exploit to gain some kind of concessions from clubs to whom they are traded.

That, at least, had been an ongoing theme for the Red Sox over the past several years. And so it was noteworthy that shortstop Alex Gonzalez, who had the right to veto a deal to Boston, sought nothing in order to accept a deal when the Sox acquired him from the Reds in exchange for minor-leaguer Kris Negron on Aug. 14.

“They called me and I was surprised. After three years, they wanted me back,” said Gonzalez. “I didn’t think about it. They just wanted me. My agent said, ‘It’s a great opportunity for you to go back there and make the playoffs.’ I said, ‘Yeah.’ I wanted to go back there.”

Granted, Gonzalez was amidst a difficult return to the majors with Cincinnati after missing all of 2008 with a fractured knee. He was hitting .210 with a .258 OBP and .296 slugging mark, and he cleared waivers in August – thereby making him available when the Sox came calling – when no team was willing to pick up the remainder of his salary. The Reds, in fact, ended up contributing more than $1 million to the Sox to pay part of the remaining obligation to the shortstop.

Even so, Gonzalez made clear that he sought no concessions – no money, no agreement that the Sox either exercise or decline his $6 million option for the 2010 season – when Boston moved to get him.

“I didn’t ask for money,” said Gonzalez. “I didn’t ask for anything.”

Of course, even though Gonzalez enjoyed his time as a member of the Red Sox in 2006, there was at least some cost-benefit analysis involved before he agreed to sign off. But that calculation was simple: Gonzalez had the opportunity to go from a dismal Reds team with a 50-64 record, 13 games back in the N.L. Central, to a 65-49 Sox club that led the wild-card standings.

As such, he and agent Eric Goldschmidt recognized an opportunity not only to enjoy greater on-field happiness, but also the potential to increase the shortstop’s stock should the Sox decline his 2010 option and make Gonzalez a free agent.

“When you have the opportunity to go from a club that’s 20 games under .500 to, in all probability, a playoff club, that makes it easy,” said Goldschmidt. “It generally helps a player. If a player can perform well in Boston or New York and play well or at a high level in the postseason, as Alex did in Florida, I think it only can increase the value of the player.”

 “Being a professional player,” added Gonzalez, “if you go and play in Boston you’ll have 28 more teams (in addition to the Sox and Reds) watching you play hard.”

Thus far, Gonzalez has done just that. He has delivered sterling defense, as well as surprising offense. Even though his 12-game hitting streak came to an end on Thursday, the shortstop’s production has still represented an unexpected bonus for the Sox, as he’s hit .282 with four homers and a .776 OPS (albeit without a single walk in his 88 plate appearances with the Red Sox).

In so doing, he has improved both his team’s position in the playoff race, found renewed life for his season and potentially improved his standing should he be on the market this winter. As such, Gonzalez has not had a single moment of regret about waiving his no-trade clause.

“I was excited for the Red Sox organization to bring me back,” said Gonzalez. “I came here to play baseball, help the team make the playoffs and hopefully win the whole thing.”