Greg Monroe of the Detroit Pistons drives against Carlos Booze...

Greg Monroe of the Detroit Pistons drives against Carlos Booze of the Los Angeles Lakers at Staples Center on March 10, 2015 in Los Angeles, California. The Lakers won 93-85. Credit: Getty Images

There was a flurry of activity Wednesday on the first full day of NBA free agency, but the Knicks didn't add anyone and lost out on two potential targets.

North Babylon's Danny Green agreed to return to the Spurs for a reported four-year, $45-million deal. Another two-way wing player, DeMarre Carroll, left Atlanta for Toronto and a four-year, $60-million contract.

These transactions likely will make the Knicks up their pursuit of Portland shooting guard Arron Afflalo. A source close to Afflalo thinks he "would be a great fit'' with the Knicks. He played with Carmelo Anthony in Denver, and would add much-needed shooting and defense.

But the Knicks' primary focus is adding a center, and they were the first to meet with Greg Monroe to tip off free agency as the clock struck midnight Tuesday. Team president Phil Jackson, general manager Steve Mills and coach Derek Fisher were in Washington to speak with Monroe and agent David Falk.

Monroe has long been considered a likely candidate to join the Knicks. But the Pistons big man met with the Bucks after his sit-down with the Knicks early Wednesday morning, followed by the Blazers and Lakers.

According to Yahoo Sports, Milwaukee and Portland had made "significant inroads'' with Monroe. The Blazers are hopeful they can keep LaMarcus Aldridge and pair him with Monroe.

The Knicks will visit with Clippers free-agent center DeAndre Jordan in Los Angeles Thursday and also with Aldridge. They also planned to meet with Portland center Robin Lopez while in L.A.

Jordan and Aldridge were seen as long shots for the Knicks. The Clippers and Mavericks have been mentioned as the front-runners for Jordan. The Lakers and Spurs were believed to be Aldridge's top two, but the Los Angeles Times reported Aldridge will not join the Lakers.

The Suns agreed on a four-year, $52-million deal with former Knick Tyson Chandler, but the Spurs offer Aldridge the best chance to win a championship. Their recruiting contingent featured coach Gregg Popovich, Tim Duncan and Tony Parker.

The Knicks should have roughly $27 million to use in free agency and hope to get three starting-caliber players with that. If they can land Monroe, Lopez and Afflalo, it will be a relatively successful offseason.

Other possible targets are Portland shooting guard Wesley Matthews and restricted free agent and former Half Hollow Hills West star Tobias Harris.

Matthews is being pursued by the Mavericks and Raptors, among others, and reportedly is seeking $15 million a year. He's returning from a ruptured Achilles, and his price may be too high for the Knicks because they likely will have to pay maximum or near-max salary to a big man.

The Knicks reached out to Houston restricted free-agent point guard Patrick Beverley and shooting guard Willie Green, league sources said. There is mutual interest with Beverley and the Knicks, but the Rockets can match all offers.

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