BOSTON – Boston Red Sox owner John Henry defended the choice of club director George Mitchell to head baseball’s steroids investigation, saying Monday he wants to know if any players – including his own – used banned substances.

Commissioner Bud Selig appointed the former Senate Majority Leader on March 30 to lead the investigation. It will, at first, deal only with events since September 2002, when the sport banned performance-enhancing drugs, but Mitchell can expand its scope.

The appointment was criticized by those who felt Mitchell’s role on the Red Sox might compromise his independence.

“Is it such a conflict? We had the same feelings about this issue as the commissioner does,” Henry told The Associated Press during an interview in his Fenway Park office.

Henry was the owner of the Florida Marlins, and Mitchell was on their board of directors, before Henry took over the Red Sox in 2002.

“If somebody on any team is using illegal substances we want to know about it and it should be dealt with,” Henry said, speaking one day before Boston’s home opener against Toronto.

He also voiced support for the toughened penalties for players who violate the ban against steroid use. Players will be suspended 50 games without pay for a first offense and 100 for a second offense. A third positive test would result in a lifetime ban.

When the steroid investigation was announced, the choice of Mitchell was criticized by Sen. Jim Bunning, a Kentucky Republican and a baseball Hall of Famer, and John Dowd, who headed baseball’s investigation of Pete Rose’s gambling in 1989.

“I think people who took a shot at George because he might have a conflict of interest, that’s really unfair,” Red Sox chairman Tom Werner said. “If he could figure out a way to bring the Protestants and Catholics together after hundreds of years of bloodshed in Northern Ireland, and his idea for the Mideast peace plan was accepted by the Palestinians and the Israelis, there’s no finer person, and he’s a former prosecutor. Plus, he loves baseball, so he’s got the interests of the game at heart, so you couldn’t pick a better choice than George.”

Mitchell has said he won’t resign as a director with the Red Sox and doesn’t think there’s a conflict of interest.

“He’s on his own,” Selig said Monday in St. Louis. “It is really going to be a thorough investigation, unimpeded by anything or anybody.”

With Barry Bonds seven homers away from passing Babe Ruth’s 714, second most in baseball history, Henry wouldn’t discuss how baseball should handle the possibility that Bonds might pass Ruth and Hank Aaron’s 755 homers.

“I’m just not going to comment on Barry Bonds or steroids,” Henry said.

His fifth season as owner of the Red Sox got off to an outstanding start. They were 5-1 on the road and, on Monday signed David Ortiz to a contract extension through 2010 with a club option for 2011.

On Tuesday, former Marlins ace Josh Beckett pitches in front of a home Fenway crowd for the first time. Beckett was obtained on Nov. 25 in a trade after Theo Epstein stepped down as general manager on Oct. 31. Epstein returned to his old job on Jan. 24 after issues involving his relationship with team president Larry Lucchino were addressed.

“At some point last year, growing over a period of time, there were issues that I think neither one of them really wanted to address with each other because they’ve worked together” a long time, Henry said. “So getting them out and discussing them, it was great.

“The end result is we have an incredibly strong organization, stronger than ever before. When we went to spring training, that’s how we felt. That’s how we feel with opening day tomorrow” at Fenway.

Epstein began his baseball career as an intern in 1992 with the Baltimore Orioles where Lucchino was president. Epstein went to the San Diego Padres in 1995, the same year Lucchino became their president, and moved to the Red Sox when Lucchino went there as part of Henry’s team.

“I’ve never felt better about this franchise than we feel today,” Henry said.

When the sale to his group was closed on Feb. 27, 2002, some Boston fans viewed him as an outsider and favored a local group that bid for the franchise. Both Henry, who had owned the Marlins from 1999 through 2001, and Werner, former owner of the Padres, came from small markets.

“When we bought the team, that’s what was speculated upon, (that) we borrowed so much money we wouldn’t be able to make payroll or we wouldn’t be able to have a payroll. We were small-market guys,” Henry said, “but, no, it hasn’t been a financial burden.”

Last year and again this season, the Red Sox payroll was second in the majors only to the New York Yankees.

In Henry’s third season, 2004, the Red Sox won their first World Series in 86 years. Last year, they won the AL wild-card berth but lost in the AL division series to the Chicago White Sox, the eventual champions. After the 2005 season, fan favorite Johnny Damon signed with the Yankees and Epstein surprised Henry by leaving before coming back.

“Could you imagine a better script than that?” Henry said of his eventful tenure. “I love to see it. Do you realize that today on the front page of the Boston Globe was an article about how they found people who weren’t Red Sox fans? Would you ever see that anywhere in the country in any sport? So that pretty much sums it up.”