MILWAUKEE— The Milwaukee Bucks are getting a much-needed big man and the Houston Rockets are positioning themselves to make a big move.

A person with direct knowledge of the deal said Wednesday that the Bucks and Rockets had agreed to a trade a day before the NBA draft, with the Bucks sending the No. 12 overall pick and three players to the Rockets for the No. 14 pick and center Samuel Dalembert. The Rockets get guard Shaun Livingston and forwards Jon Leuer and Jon Brockman in the deal.

The person spoke to The Associated Press on condition of anonymity because the deal was not yet official. Several media organizations reported the deal earlier Wednesday.

Dalembert has career averages of 8 points, 8.2 rebounds and 1.9 blocked shots per game. Center is a major need for the Bucks, who traded away Andrew Bogut last season and never really found a way to replace him.

Houston, meanwhile, is apparently positioning itself for a blockbuster move after dealing Chase Budinger to Minnesota for the 18th pick on Tuesday. The Rockets now have the No. 12, 16 and 18 picks in Thursday’s draft, but the team may make more moves as they put together a package to land a superstar big man — possibly Orlando’s Dwight Howard or Atlanta’s Josh Smith.

Howard, a five-time All-Star center, asked to be traded by the Magic during the season.

The Rockets went 34-32 last year, missing the playoffs for the third straight season. They’ve lacked a strong inside presence since former top overall pick Yao Ming started running into foot and injury issues and finally retired last summer.

Before last season, the Rockets were ready to trade forward Luis Scola, shooting guard Kevin Martin and point guard Goran Dragic for Pau Gasol, but NBA commissioner David Stern nixed the trade for “basketball reasons” on behalf of the league-owned New Orleans Hornets.

Houston picked up Dalembert in December. He started 45 games and averaged 7.5 points and seven rebounds per game in 2011-12.

First-year coach Kevin McHale said at a charity event on Monday that finding a dominant big man remains a high priority.

“From my standpoint,” he said, “getting bigger, protecting the rim, playing above the rim, rebounding and blocking shots is always a good thing.”

Howard was been named the league’s top defensive player three times and averaged a career-high 14.5 rebounds per game last season. He also publicly expressed frustration with coach Stan Van Gundy and general manager Otis Smith during the season. Van Gundy was fired and Smith parted ways with the team in May.

Speculation swirled this week that the Rockets were shopping point guard Kyle Lowry, who missed 19 games last season, mostly due to a bacterial infection that required hospitalization. Lowry and McHale developed a rift, arguing during a timeout in a game against Denver in April. Lowry told the Houston Chronicle in May that he would have “issues” playing for McHale.

With Lowry sidelined, Dragic emerged as a capable replacement, averaging 18 points and 8.4 assists in 28 starts. Dragic is an unrestricted free agent, but said after the season that he’d like to remain in Houston. He also said he wants a starting role in the NBA.

Bucks general manager John Hammond emphasized this week that he and his staff would take the best player available in the draft, conceding that the Bucks absolutely needed to find a center.

“I think right now there’s the assumption that we’re kind of looking into basically a narrow-minded set of, ‘We have to go big,’” Hammond said. “You know, there’s a need there, so obviously that is going to be a discussion and it’s going to somewhat of a priority for us.”

Before moving to get Dalembert, players projected to be of interest to the Bucks were North Carolina center Tyler Zeller and Illinois’ Meyers Leonard. Both run well for 7-footers, a must on a team that wants to play with an up-tempo style powered by guards Brandon Jennings and Monta Ellis.

Milwaukee also could go with a shooting guard such as Connecticut’s Jeremy Lamb or Washington’s Terrence Ross.

Hammond and coach Scott Skiles both are going into the final year of their contracts and aren’t considered likely to receive extensions before the season starts. Given the uncertainty, Hammond might be expected to favor drafting a player who can help the team right away over a project with a higher upside.

But Hammond said his contract situation won’t change the way he approaches the draft, even if fans and the media are discussing it.

“The issue at hand is how can we improve the Milwaukee Bucks,” Hammond said. “So for us, that may be discussed at the draft, it may be discussed during free agency, discussed even during the season when we talk about trades or other things that could come our way to change our roster. But at the end of the day, it’s about doing the right thing. And the right thing is what’s best for this team, this organization, this city and our fans. And I would never vary from that.”