HOUSTON — Prior to Monday night’s tipoff, Knicks interim coach Mike Miller said his depleted club would face two “Hall of Fame guards” in their matchup with the Rockets at Toyota Center.

As it turned out, it was just one Hall of Fame guard. While Russell Westbrook sat out with a thumb injury after earlier attending the Kobe Bryant Memorial in Los Angeles, a travel-weary James Harden decided to play and put on his usual clinic against the Knicks.

From inside and outside, Harden burned the Knicks for 31 points in the first half on the way to a 37-point, nine-assist evening as the Rockets won in a 123-112 rout.

“He’s a great player [but] as strange as it sounds, we gave too many easy baskets,’’ Miller said. “There were four, five coverage plays in the first half, there were a couple of straight ‘got beat off the dribble.’ You can’t give those away. He got too many easy ones early.’’

The Knicks (17-40) lost their fourth straight to hit the 40-loss mark and played without their top two point guards in Elfrid Payton (ankle sprain) and Frank Ntilikina (sore groin).

Dennis Smith Jr. made his third start at the point but couldn’t do much against Harden nor could rookie RJ Barrett, who essentially was the backup point guard.

Knicks
Dennis Smith Jr. and the Knicks lost to the Rockets on Monday.AP

Smith and Barrett still had lively games. Smith notched 15 points, seven steals, five assists and seven rebounds. RJ Barrett added 21 points on 8 of 17 shooting with three assists and five turnovers. He cooled off after a blistering first quarter attacking the rim.

“The lanes were open early in the beginning,’’ Barrett said. “They put bigger stronger guys on me. They tried to just pack the paint in.’’

After Harden obliterated the Knicks in the first two quarters, Miller made the halftime adjustment.

The Knicks dedicated the second half to throwing two and often three bodies at Harden, trapping him at the perimeter to get the ball out of his hands. It worked to limit his point total as Harden was 2 of 8 for six points in the second half, with Maurice Harkless doing a nice job containing the lefty bearded wonder.

Barrett said he learned stuff from facing Harden for the first time. The Knicks host Houston on March 2.

“Man it’s tough to guard him one-on-one so the second half we started trapping him but the rest of his teammates were still going,’’ Barrett said.

Harden, a Los Angeles native, considered Bryant his No. 1 idol and they became very close in recent years. Harden, Westbrook and P.J. Tucker were in Los Angeles and took a three-hour charter flight back to Houston for the game. They arrived at the arena 70 minutes before tipoff.

Harden hit 12 of 16 baskets by intermission — 4 of 5 from the 3-point line. He danced through Knicks defenders for runner after runner, layup after layup.

“Long, very, very emotional day,’’ Harden said. “It’s to pay our respects, show my condolences to the family. It’s a tough time for them, for the entire world. It’s a must that I be there and show my respect.’’

One of Harden’s 3-pointers was controversial as he deked and elbowed Smith in the stomach. Smith flopped and the fans cheered as Harden sank the wide-open 3 with Smith on the floor.

Smith wasn’t going to complain.

“If he gets the benefit, he deserves to get it,’’ Smith said. “He’s the MVP. He earned the right to get the benefit of the doubt with those kinds of calls.’’

Harden was on pace at halftime to surpass the 61 points he racked up at the Garden on Jan. 23, 2019.

With the depleted point-guard situation that included two-way player Kadeem Allen’s concussion, Barrett took on backup point-guard duties. He was powerful and crafty on his forays to the basket, hitting 6 of 9 from the field for 16 first-half points.

The Knicks hung around, were within six points midway through the second quarter and got within eight late in the third quarter. But the Rockets’ Austin Rivers (14 points, 24 minutes) got hot and Houston led 101-86 entering the final frame. Ben McLemore added 17 points and Eric Gordon 16 points.

“It wasn’t anything to write home about but we got the win,’’ said Rockets coach Mike D’Antoni, the former Knicks coach.