The center believes Houston will be better without the young small forward next season.
Parsons joined the Dallas Mavericks in free agency after the Rockets decided not to match a three-year, $45 million contract offer. He put up career highs with 16.6 points, 5.5 rebounds and four assists last season.
Howard believes, however, that the 25-year-old will not be missed.
"It won't affect us at all," Howard said at his basketball camp in Atlanta. "We have myself and James [Harden]. We have the best center and the best two-guard in the game on the same team. It's on us."
The Rockets replaced the Parsons with veteran swingman Trevor Ariza, who played with Howard in Orlando early in his career.
"He'll go through a wall for you," Howard said of the former Lakers and Wizards wing. "Just to have soldiers on your team like that is great. We have that one-two punch with me and James. We're filling out our roster with guys who are willing to go through that wall and doing whatever it takes to win."
Howard is talking up the combination of himself and Harden as the best one-two punch in the NBA, but their performance last season did not live up to that status.
After reaching the playoffs as a four seed, the Rockets lost their first-round matchup with the Portland Trail Blazers in six games.
Howard averaged 18.3 points, 12.2 rebounds and 1.8 blocks per game last season, all down from his best years with the Magic, but was handed All-NBA Second Team honours.
If Howard is to return to the throne as the best center in the NBA he must, along with Harden, lead the Rockets further in the playoffs than last season.
The Western Conference is extremely tough, but to be considered a better combination than Tony Parker and Tim Duncan, Russell Westbrook and Kevin Durant or Chris Paul and Blake Griffin, the Houston tandem must at least advance to the second round in 2015.