With the loss, Calgary closes out a five-game road trip with a 2-1-2 record for six of a possible 10 points.
"It was a pathetic effort by us," Zadorov said. "First two periods, for sure. We were a step behind. Energy wasn't there, commitment wasn't there, we weren't shooting, we were making bad plays, giving up too many chances. Just all-around, bad effort for us.
"No excuse. We have a goal. We have a gameplan and know how we should play and have to play.
"It just wasn't there tonight."
Trailing 2-1 entering the third period, the Flames had a glorious chance to equalize when Craig Smith (tripping) and Tanner Jeannot (delay of game) were ushered to the box only 18 seconds part, putting the Flames on an extended 5-on-3.
The two-man was briefly interrupted when Rasmus Andersson took a high-sticking minor, but they still had 1:25 on the 4-on-3 to work with.
Tyler Toffoli appeared to bring the Flames back on even terms, but a review confirmed the puck was kicked in and played on in a one-goal game.
"I didn't like the goals against in the first period and thought when you take a penalty on a 5-on-3 when it's 2-1... you're probably not in the right mindset," said Head Coach Darryl Suter.
Despite outshooting the Predators 21-5 in the frame, the Flames were unable to tie it up.
With the loss, the Flames drop to 21-15-9 on the year.
"The game tonight was to make it not 'good,' (but a) 'great trip," Zadorov said. "We didn't get two points, so it's just a good trip."
The Predators had a territorial edge early, and after peppering Markstrom with seven of the first 11 shots of the contest, Josi put the homeside up 1-0 at 8:26. The Nashville captain - who put up a career high 96 points last year - unleashed a one-timer that appeared to be drifting wide of the cage, but banked in off the backside of Zadorov, who had dropped to a knee in a battle with Cody Glass at the doorstep.
A turnover inside the Flames blueline nearly put the Preds up by two shortly thereafter, as Filip Forsberg rifled a shot into the pads from the far circle. William Carrier drove hard to the paint and looked to deposit the rebound, but Zadorov tracked back and made a fabulous defensive play to knock Carrier off rhythm.