HOUSTON – Boston big man Al Horford said he was impressed with the Houston Rockets' free-agency pitch over the summer.

It was a difficult decision for Horford, whose dad wanted him to play for the Rockets.

Horford, who eventually signed a four-year, $113 million deal with the Celtics, had one of his first free-agent meetings with the Rockets, with Hall of Famers Hakeem Olajuwon and Clyde Drexler among those in attendance.

Al Horford said it wasn't easy letting his dad know that he chose the Celtics over the Rockets. Brian Babineau/NBAE via Getty Images

“It was a privilege,” Horford said. “[Olajuwon] and Clyde were there, and my dad went to high school [Marian Christian] here in Houston, and he was pushing Houston hard. Hakeem, to him, was a big deal, and for me to be able to talk with him and spend some time. At the end of the day, just looking at the future and everything, I felt like here in Boston was going to be a better fit for me in the long run.”

Rockets guard James Harden was also part of Horford's recruitment.

“I thought we had a really good chance, but obviously it didn’t work out, which is fine,” Harden said.

Horford said the toughest thing was making the phone call to his father telling him he wouldn’t sign with the Rockets.

“Definitely my dad, he loves it here,” Horford said. “We have a lot of friends of the family here who live in the area, and he was heartbroken. He’s happy for me at the end of the day -- it was definitely a tough call.”

The Rockets had to move on and signed power forward Ryan Anderson and guard Eric Gordon as their two big free agents. The team also stuck with third-year man Clint Capela as the starting center to replace Dwight Howard, after Horford elected to sign with Boston. Howard would sign with Atlanta, replacing Horford.

Capela is third in the league in field goal percentage (.631), and over the past 10 games he has averaged 14.4 points, 2.1 blocks and 8.6 rebounds.

Monday night, Capela will face Horford at the Toyota Center.

“I feel pretty good, and I felt like I’ve had an impact on the stuff I'm supposed to do," Capela said. “Running the floor, block shots, defensive end, just every game, start at zero and stay focused and just play as hard as I can.”