James Harden played 78 games last season, 72 the season before that (which was impacted by a strained hamstring), and either 81 or 82 games the three seasons before that. The former MVP does not take time off and has said before he wouldn't do load management.
In the wake of the pointless discussion around Kawhi Leonard sitting out half of a back-to-back Wednesday vs. Milwaukee, Harden was asked about rest and said exactly what you would expect him to say - he's not doing it. Via Michael Shapiro of SI Now:
No, I have not seen Harden take a load management game.
I have seen him fade and hit a wall deep in the playoffs, as the heavy load he was asked to carry too long finally caught up with him. The Rockets have suffered for it.
The hard-data science on the value of load management is not conclusive. However, teams have bought in. It's not an accident the Spurs run seemed extended by it, that other elite players such as LeBron James - guys asked to take on heavy playoff loads - are better for being rested and healthy before the playoffs started, and that the Raptors' load managing Kawhi Leonard last season played a role in his Finals MVP and the Raptors' title.
There was talk that the Rockets would try to load manage Harden and Russell Westbrook some this season, but there was also pushback on that report.
Any rest is not going to happen this early in the season because the Rockets are still a work in progress in terms of chemistry and rotations. Houston needs Harden and Westbrook on the court (and more out of Clint Capela, but that's another discussion). The Rockets are still finding their identity - and searching for their defense - this season.
However, as the calendar moves along and flips over to 2020, having Harden miss a handful of back-to-backs or other games could be beneficial in the long run. The Rockets see themselves as contenders, but to push the Los Angeles teams a lot of things need to come together in Houston - and they will need full MVP Harden deep into the playoffs.
Harden, however, wants no part of this load management talk.