Memphis was 11-7 when Mike Conley went down, and the point guard’s back injury should keep him out of action until MLK Day, or perhaps longer. The best-case scenario for the 6-8 weeks Conley was expected to miss was for the Grizzlies to end up pretty close to .500.

Instead, the Grizzlies are nine games over .500, and sit within a half game of the No. 3 seed. They’ve now won six straight and are 6-1 since losing Conley.

Along the way, Memphis has continued its dominance in close games for what seems like the umpteenth straight season. To date, Memphis is 12-0 in games decided by no more than five points or settled in overtime.

How are the Grizzlies doing this? The same way most underrated teams do it: defense.

Per NBA.com/stats, Memphis’ top-ranked defense is the only one in the league allowing fewer than 100 points per 100 possessions (99.5). Two defenses pulled off that feat last season, and a whopping five were under that mark by the 2016 All-Star break.

Offenses on the whole have performed much better this season; the Grizzlies have been the stalwarts resisting against the a new NBA paradigm. Memphis also happens to have the third-slowest pace in the league. Grit ’n Grind survives, despite a move toward smallball.

The Grizzlies have tightened the defense up even more since Conley went down, allowing just 98 points per 100. That number’s a bit misleading, as four of those seven games came against weak offenses (Magic, Lakers without D’Angelo Russell, Pelicans, Sixers). In their only loss without Conley, Memphis gave up 120 to Toronto’s top-ranked offense.

But in the Grizzlies’ last two games, the defense held Portland’s No. 8 offense 17 points per 100 under its typical production and Golden State’s No. 1 offense 22 points per 100 under its typical production.

We knew the Grizzlies had a strong defense before they lost Conley. When fit, Marc Gasol is one of the best defensive centers in the NBA. When healthy, Tony Allen can still lock down a wide assortment of wings. Zach Randolph is a tough rebounder, JaMychal Green is a versatile defender, and rookie coach Dave Fizdale has shown an affinity for that side of the court.

Conley is a far superior offensive player to any other guard on the Grizzlies’ roster and he was having an All-Star caliber season before going down. His replacement, Andrew Harrison, is shooting 28 percent from the field (that’s not a typo) and is just a middling passer. It’s a massive offensive drop-off.

But Harrison can defend. Since defense is how Memphis wins this season, and since the drop-off isn’t so steep on that end, the Grizzlies can survive just as long as they get enough offense out of Gasol, Green, and Z-Bo.

You know who else can defend? The other nameless standbys in Memphis. Most NBA fans have heard of JaMychal Green by now, but James Ennis? He was the starting small forward before injury struck in late November. Troy Daniels? A key reserve on his fourth team in four NBA seasons. Troy Williams? An undrafted rookie out of Indiana who has more starts than any 2016 top-10 pick other than Marquese Chriss. Jarell Martin? A late 2015 first-round pick who is giving 15 minutes of hard effort to Fizdale every night. Even 20-year-old project center Deyonta Davis is contributing a bit.

You don’t hear these names too often because they do very little that is glamorous. Even hardcore NBA heads didn’t notice Williams ... until he locked up Draymond Green in the Grizzlies’ blowout win over the Warriors on Saturday. That’ll turn some heads. So will this.

Under GM Chris Wallace Memphis has constantly won by valuing the undervalued, and what’s more undervalued than defense? Even a superstar defender like Allen costs a fraction of what equal-value offensive players rate. The only max-contract defenders you’ll find are two-way superstars like Draymond or Kawhi Leonard, or elite defensive 7-footers like DeAndre Jordan and Rudy Gobert. Shutdown wings are much more affordable, though still rare.

Defense is so undervalued. This is how Draymond goes in the second round, Kawhi falls to No. 15, and a high-potential defender like Williams goes undrafted. This is how the Grizzlies win six straight with a bevy of anonymous kids. (Well, this plus Marc Gasol playing out of his mind.)

If they keep it up, people will know their names soon enough. Just ask Draymond and the Warriors. They found out who Memphis is on Saturday.