HOUSTON -- The Houston Rockets expect to be active players in the free-agent market that opens Friday. According to a source, they will push heavily toward signing either Al Horford, Kevin Durant, Hassan Whiteside or Ryan Anderson.

It's unknown if the team has scheduled visits with these players; however, ESPN's Marc Stein reported Durant's initial free-agent visits don't include the Rockets.

The Rockets' search will be broad in attempting to upgrade a roster that finished 41-41. There's also an outside chance the team will also explore looking at point guards Jeremy Lin and Mike Conley in free agency.

Lin appears to be a better fit with the Rockets' offense given his success under it when he played for Mike D'Antoni in New York.

The Rockets drafted two centers in last week's draft, but general manager Daryl Morey said those picks won't affect what the team does in free agency.

Houston would like to find a better solution at power forward. It used four starters at the position this past season, outside of moving Trevor Ariza to the spot to go with a smaller lineup for a variety of reasons from injury to ineffective play.

The Rockets will have roughly more than $45 million in cap space to sign one or possibly two high-level free agents.

Rockets guard James Harden said he will be an active recruiter in free agency for the team. He said he's bypassing a chance to play for the U.S. Olympic team to concentrate on helping the team. Harden said he will try to convince Durant to consider signing with the Rockets and will also recruit other free agents if asked.

"Last year was very frustrating as an organization in Houston," Harden said. "So for me, I think trying to get our winning ways back and back to championship ways. Just being part of that free-agency process and trying to get guys to Houston and trying to win. I think that right now is something I'm trying to focus on."