GREEN BAY, Wis. -- Here’s how Green Bay Packers special teams coach Ron Zook summed up his units shortly after the regular season ended last month:

“I feel we’ve made progress,” Zook said as the Packers prepared for the playoffs.

At least one set of rankings says differently.

Zook’s units finished 29th in the NFL in the Dallas Morning News’ annual special teams rankings. That represented a significant slide from where the Packers were in Zook's first season, 2015. Zook replaced Shawn Slocum, who was fired following the 2014 season. In Slocum’s last year, the Packers finished 32nd -- or dead last -- in those same special teams rankings, and that didn’t include the meltdown in the NFC title game when the Seahawks pulled off a fake field goal for a touchdown and recovered a late onside kick to help force overtime.

Zook’s first season saw the Packers jump to 17th -- their highest ranking since 2012 (when they were 12th).

“Honestly, the key is you’ve got to continue to make progress,” Zook said. “I say it all the time, we don’t get second down or third down. We’ve got one down, and that’s usually a long play and we have to play at a [certain] level.”

The annual special teams rankings take 22 categories into consideration. The Eagles graded out as the league’s top special teams outfit; the Chargers were the worst.

For the Packers, when you’re better than only three teams in the league -- only the Jets, Cardinals and Chargers ranked below Green Bay -- there’s plenty to work on. But if there’s one area that stands out, it’s kickoff coverage. The Packers allowed a league-worst 26.3 yards per opponent kickoff return. Not surprisingly, they also ranked last in opponent starting field position after kickoffs, the 26.6-yard line.

Zook would be hard-pressed to blame injuries for the drop in his special teams. The Packers used the same number of players -- 53 -- on Zook’s units that they did each of the previous two seasons, compared with 58 players used on special teams in 2013.