(The Washington Post/Richard A. Lipski)

Linebacker Lorenzo Alexander agreed to a contract Wednesday with the Arizona Cardinals, leaving the Redskins in free agency.

The Redskins wanted to re-sign Alexander, their special teams captain and a Pro Bowl selection on special teams this past season. He also made some significant contributions on defense in part-time duties and was one of the team’s locker-room leaders.

But Coach Mike Shanahan said Monday, on the eve of the opening of the free agent market, that he didn’t know if the Redskins could compete financially to retain Alexander.

By Tuesday, it was clear that Alexander was likely to sign elsewhere. He also was pursued by the San Francisco 49ers and Pittsburgh Steelers. Former Redskins special teams coach Danny Smith now holds the same job in Pittsburgh.

Alexander tweeted following message:

@onemangang97: It’s official, I’m an Arizona Cardinal! I appreciate all the love an Support I received in DC.

Alexander’s three-year deal with the Cardinals is worth $9.5 million, including $3 million in guaranteed money, a person familiar with the deal confirmed Wednesday night. He could be in line for a starting job on defense in Arizona. He told 106.7 The Fan in an interview at the players’ union meetings in the Bahamas that he was prepared Monday to re-sign with the Redskins before the team lowered the amount of guaranteed money in its offer from $2.6 million to $1.4 million.

“Dropping more than a million dollars overnight without any reason, I couldn’t take that money out of my kids’ mouths,” Alexander told the radio station in comments published on its Web site. “Based on everything I’ve done [for] this organization, doing everything the right way, it was just a bad way to treat me. I understand the business, but… it didn’t sit right at all with me.”

Alexander failed to return phone and text messages.

The Redskins denied Alexander’s assertion that they abruptly lowered their offer to him.

“It is not true,” team spokesman Tony Wyllie said.