Question: How long does it take to shake off 21 days of rust?

Answer: For the Auburn offense, a little less than 18 minutes. For the defense, apparently longer than a game.

“The 1st quarter, we were sleepwalking a little bit,” Tigers coach Gus Malzahn said after Saturday’s 30-17 win over Tennessee. “The 2nd quarter we woke up, and started playing Auburn football.”

Auburn returned to action for the 1st time since Halloween, and the performance was up and down, as one would anticipate coming back from a 3-week hiatus. No one wanted to tackle on defense, and the offense was a little flummoxed to start. But Auburn avoided a letdown as they prepared for their biggest game of the season — next week’s Iron Bowl against Alabama.

Bo Nix continued to show progress in his 2nd season. After starting the game 3-of-7 for 31 yards and throwing his 1st-ever interception inside Jordan-Hare — in very Bo Nix fashion, while on the run without his feet set — the sophomore QB went on to hit his next 14 of 19 passes for 189 yards and a touchdown as the Tigers scored 27 straight points.

After opening the season with 4 straight games with a completion percentage of less than 61, Nix has strung together a 3-games stretch in which he has completed 72.5 percent of his throws. He has shown more patience in the pocket, and the potential for a deep strike has quickly emerged as a legitimate threat for Auburn following consecutive games in which Anthony Schwartz has scored on receptions of greater than 50 yards.

For the 4th straight game, Auburn averaged more than 4 yards a carry. That’s a sizable accomplishment against the Volunteers given the litany of injuries the Tigers offense sustained.

Wunderkind tailback Tank Bigsby was all but absent for the entire game due to a hip injury on the 1st drive. Yet D.J. Williams chipped in with 66 yards and Shaun Shivers with 65 behind a patchwork offensive line that was forced to find replacements for Brodarious Hamm and Alec Jackson mid-game. Receiver Seth Williams also suffered an injury late in the game.

But while the offense should inspire some confidence leading into the Iron Bowl, the run-stopping woes displayed against Eric Gray should be reason to sound the alarm in preparation for Najee Harris.

If we’ve learned anything from the COVID-shortened offseason, it’s that tackling probably was affected by a lack of practice more than anything. With practices canceled and no telling which players missed time over the layoff, Auburn’s performance against the run was as embarrassing as when they allowed Mississippi to rush for 283 yards and 3 touchdowns.

Gray rushed for nearly 8 yards a carry en route to 173 yards as he put together the best game on the ground that any single player has had against Auburn all year.

Tennessee also managed to convert 9 of 15 3rd-down attempts after entering the game 118th in the country converting just 27 percent of the time.

Yet as effective as Tennessee was at moving the ball on the ground and hitting short and intermediate routes with Jarrett Guarantano like it was 2018, it was ultimately a bend-but-don’t-break-type defense for Auburn, summed up by the Vols’ 10-play, 63-yard drive that ended with a 100-yard interception return for 6 by Smoke Monday and a 3rd quarter in which Tennessee rushed for more than 100 yards but failed to score a single point.

Auburn’s defense played well enough to force Vols coach Jeremy Pruitt to send in Harrison Bailey for Guarantano.  But the inexperienced freshman QB made pretty light work of the Auburn defense, completing 7 of 10 passes for 86 yards.

It’s definitely not what you want to see with the most potent offense in the SEC on deck. But the Tigers could have easily had another interception from Nehemiah Pritchett, and safety Jamien Sherwood should only improve after returning from injury.

Alabama dropped a frightening 63-3 score on Kentucky on Saturday and will open as a huge favorite in the 85th edition of the Iron Bowl. But though Auburn’s game against Tennessee wasn’t picturesque, it also should lead you to believe that next week against the Tide won’t be an unmitigated failure.

Auburn’s health will go a long way toward determining how much they can make Alabama sweat. But Nix is finally beginning to play like a quarterback of a top-25 team, and the defense is never far from a game-changing play.

The win over Tennessee was not pretty, but in case you had forgotten since October, neither is Auburn football.