Nadirah McKenith watched the last 15 minutes of Wednesday’s Minnesota Lynx practice intently, like an honor student at a new school trying to catch up.

Signed to replace backup point guard Lindsey Moore, McKenith — a second-year pro cut by Washington in training camp — stood with her hands on her knees away from the other reserves. She studied how Lindsay Whalen called a play, passed the ball, then circled around to her right, pushing past two male practice players under orders to impede her.

The movements, the play calls, all of it was new to McKenith. And she had only three practices to absorb it before her Lynx debut Friday night in Seattle.

“There’s maybe only one or two things I’m familiar with,” said McKenith, who grew up in Newark, N.J. and starred at St. John’s in New York. “Other than that, everything is different.

“I’m learning it little by little. Everybody is doing a great job helping me run through all the plays and stuff, and Coach (Cheryl Reeve) has done a great job coaching me. I’m just trying to take it all in and be ready for Friday.”

McKenith is here because Reeve decided Moore, a first-round pick in 2013 (No. 12 overall), lacked the confidence and decisiveness to run the second unit. The timing stinks. McKenith is being asked to fit in with a championship team on the fly, a challenging task for anyone. And Reeve had to admit she blew it by urging the Lynx to draft Moore over Penn State’s Alex Bentley, who has been a much better pro.

“We just didn’t think that our offense was moving at a pace we wanted it to move when Lindsey Moore was running the backup spot,” Reeve said. “We felt like we had to try something. 

“McKenith’s reputation is a little more of a ball-mover, a distributor, can get to the rim, play in pick and roll game. She’s a young player. We certainly don’t view here as the magical solution. But at this point in time, with three practices, it was worth taking a look at.”

The 11-4 Lynx trail 9-3 Phoenix by percentage points for the Western Conference lead, but rank last in the 12-team WNBA in bench scoring — by a lot. The Lynx tally 12.7 points per game; the league average is 21.5.

Knee injuries to valuable reserves Monica Wright and Dev Peters contributed to that. But lately Moore struggled moving the ball against defensive pressure, and Reeve lost confidence in her. In the just-concluded stretch of six games in 10 days, Moore sat out three games entirely and played one minute in another. Reeve felt the bench needed a boost at the point. 

WNBA contracts are guaranteed for the season the day after a team’s 17^th game, the midpoint. That’s Monday for the Lynx, who finish a home-and-home set with Seattle on Sunday night at the Target Center. Waiving Moore last Tuesday saved salary while giving Reeve three practices and at least one game to evaluate McKenith, whom Washington selected five picks after Moore in 2013, in the second round. The 5-foot-7 McKenith averaged 2.8 points and 1.0 assist coming off the bench for the Mystics.

Reeve knows how this looks. Had David Kahn done this with the Timberwolves — jettisoning a former first-rounder to sign a later choice from the same draft — fans and reporters would rip him forever. Candidly, Reeve took responsibility and explained her pre-draft thinking.

The gist: Picking last in the first round, the Lynx had no shot at an impact player. Reeve researched 12^th picks in WNBA draft going back to the first in 1997, discovering a few astute choices, more misses, and no real stars. (The year before, the Lynx took Damiris Dantas at the spot, which looks pretty savvy so far.)

The Lynx settled on taking a playmaker behind Whalen, someone who could step in as a rookie and run the offense for eight to 12 minutes a game. The Lynx considered McKenith — assistant coach Shelley Patterson scouts the Big East — but rated Moore and Bentley ahead of her. 

Bentley’s modest assist average of 3.5 per game as a senior concerned Reeve, a former point guard at LaSalle. Moore, meanwhile, dished 5.7 per game at Nebraska. And Moore’s stellar performance against Texas A&M in the second round of the 2013 NCAA Tournament, scoring 20 points with 10 assists while adroitly handling ball pressure, left a big impression on Reeve. So the Lynx took Moore, leaving Bentley for Atlanta, which chose her with the first pick in the second round.

It didn’t take long for Bentley to fit in. Bentley made the WNBA All-Rookie team, averaged 8.3 points and 2.8 assists for the Eastern Conference champion Dream, and displayed playmaking chops with a franchise record-tying 11 assists against Los Angeles on September 2. Traded in the offseason, Bentley averages 11.1 points and 3.7 assists for Connecticut.

And Moore? Over a season-and-a-half, she averaged 1.0 point and 1.1 assists. That’s a big miss, a rare one for a franchise that has done so much right since Reeve arrived in 2010.

“We were thinking Lindsey Moore,” Reeve said. “We spent a lot of time on Lindsey Moore and Alex Bentley. Sometimes it works out, sometimes it doesn’t.”

Now the Lynx move on. Three weeks ago, the Lynx lost 65-62 in Seattle, ending their season-opening seven-game winning streak. Reeve expects Seimone Augustus (bursitis) to play this weekend after having her left knee immobilized for two days and doing little at practice this week.

McKenith, the first St. John’s player drafted by the WNBA, had been working out at various gyms in the Newark area when the Lynx contacted her Connecticut-based agents, Billy Lovett and Oliver Macklin.

Maya Moore’s Connecticut team faced McKenith and St. John’s twice in the Big East, and Moore offered this quick scouting report: “She’s scrappy, scrappy-tough, and she knows how to play. That’s what I remember about her. And we’re seeing it again here.”

Moore already had graduated when the Red Storm upset the Huskies in Storrs, 57-56, on Feb. 18, 2012, ending UConn’s 99-game home court winning streak. McKnight drove and passed to Shenneika Smith for the deciding 3-pointer. Given Moore’s loyalty to UConn, McKenith would be wise not to bring this up.