INDIANAPOLIS — As Tim Hardaway Jr. undergoes tests to determine the extent of a stress injury to his left shin, a leading orthopedist at Northwestern University told The Post the Knicks shooting guard could be out as little as two weeks or as long as two months.

Dr. Wellington Hsu, a professor of orthopaedic surgery who wrote a paper on basketball leg fractures, said there are two types of stress injuries — a stress reaction and a stress fracture.

A stress fracture is such “a small break’’ that only an MRI exam or bone scan can determine this type of hairline fracture, according to Hsu.

If Hardaway does have a stress fracture in his shin he would miss about two months, Hsu said.

A player can still run with a stress fracture but “if you keep playing on it, it will lead to a complete fracture and end your year,’’ Hsu said.

The hope for Hardaway is either of the shin’s two bones — the tibia or fibula — only has a stress reaction.

“It’s no break, just swelling in the bone,’’ Hsu said.

A stress reaction can lead to a stress fracture if it isn’t rested. However, there are varying severities of stress reactions.

“There’s piddly ones and really bad stress reactions,’’ Hsu said. “It could just be a small area of swelling and that’s a different type of animal as someone who has swelling in the entire bone.’’

A major stress reaction would require Hardaway rest for four-to-six weeks, Hsu estimated. However, Hsu said it’s more common for the stress reaction to be minor with just one-to-two weeks of rest required.

There was no update on Hardaway’s timetable before the Knicks faced the Pacers on Monday night, with the team saying he was still being evaluated. It’s possible Hardaway is seeking multiple medical opinions.

Hardaway, who is second on the team in scoring at 17.8 points per game, has missed two straight games after playing the first 21.

“I think it’s concerning to everybody, an injury that might be longer than a game or two,’’ coach Jeff Hornacek said. “He’s getting evaluated. Hopefully we’ll find out more. Tim was not only a scorer for us, he helped activity, drove to the basket. We’re hoping it’s not too long.’’

Hardaway, 25, complained of pain in his shin following practice Saturday. He has played through various leg injuries this season — fighting through a left foot ailment that resembled plantar fasciitis coupled with pain in his ankle and calf.

Hardaway sat out Sunday’s loss to Orlando, benched at the last minute after a pregame exam and didn’t make the trip here.

According to Hsu, Hardaway’s ability to play through the prior ailments could have led to a stress reaction. Surgery is not an option for either a stress fracture or reaction.

“He’s a tough kid,’’ Hornacek said. “He had ankle sprains and didn’t miss practice. He’d play through those things. It’s a good attribute to have in a guy. This could be a wear and tear. We’ll find out more.’’

Mostly in garbage time, center Willy Hernangomez, who did not play Sunday, posted a double-double — 14 points and 10 rebounds, shooting 7- of-10 from the field. … In his second straight start at shooting guard Damyean Dotson posted nine points, seven rebounds and two steals in 29 minutes. .. Ron Baker got his first taste of real action since the season’s first week as the Knicks cut the deficit in the fourth quarter. Baker had nine points, four assists and was plus-16.