The Houston Rockets are canvassing NBA teams with significant salary-cap space to individually offer center Clint Capela, guard Eric Gordon and forward P.J. Tucker as a prelude to their pursuit of a sign-and-trade deal for Philadelphia 76ers All-Star Jimmy Butler, league sources told ESPN.

The Rockets want to secure the best available first-round pick acquired for any one of three players as part of a larger deal with Philadelphia for Butler, league sources said. Redirecting salaries elsewhere for Butler could deliver the 76ers a large trade exception that it could use in acquiring a player over the course of the next year.

If Butler and the 76ers were open to the trade scenario -- and there has yet to be a formal indication the team or Butler are interested -- the Rockets would need to include two or three of those players in a deal to the Sixers or a third team to make the salaries match on a four-year, $140 million maximum contract for Butler.

Capela has four years, $66 million left on his contract, and Gordon has $14 million and Tucker $16 million over two years left on their contracts. Only $2.6 million of Tucker's second year is guaranteed.

Nevertheless, the Sixers have been expressing confidence throughout the NBA that they'll be able to sign Butler and free agent Tobias Harris to new deals, league sources said. Butler's level of interest in pursuing the Rockets' idea is unclear. League rules prohibit Butler and his agent, Bernie Lee, from discussing the deal prior to the start of free agency on Sunday at 6 p.m. ET.

Once free agency starts, however, the Rockets are determined to push the 76ers for a sign-and-trade deal that would allow the All-Star forward to join All-NBA guard James Harden and Chris Paul on the Rockets, league sources tell ESPN.

The Rockets don't have the salary-cap space to sign Butler, so they'd need the threat of the Sixers losing him for nothing to a team with the available room to motivate the Sixers into a trade.

The Sixers plan to be aggressive in signing Butler to a new deal, sources said, and could blunt a Rockets push with a full five-year, $190 million offer at the start of free agency on Sunday night. The Sixers could offer Butler a four-year, $146.5 million deal, too.

Butler would be eligible to sign a four-year, $140 million contract on the way to the Rockets. The 76ers acquired Butler in a trade with Minnesota for Dario Saric and Robert Covington in November.

The Sixers could redirect those Houston assets to third teams and create a large trade exception that it could use to absorb a player via trade.