There was a period last summer when tight end was considered the Chicago Bears' deepest positon.

But at season’s end, Chicago’s tight ends combined to catch just 60 passes for 672 yards.

Where did it go wrong?

For starters, the group’s lowest moment occurred in Week 8, when popular veteran Zach Miller -- the Bears' most productive tight end with 20 receptions for 236 yards and two touchdowns -- suffered a gruesome dislocated knee that required emergency surgery to save his left leg.

Without Miller, 33, the Bears lacked a proven leader at the positon, and they also lost their most talented and reliable pass-catching tight end.

An unrestricted free agent, Miller’s football career is at a crossroads, but his life after football appears bright.

Further complicating matters last season was the fact that starter Dion Sims, whom Bears general manager Ryan Pace signed to a three-year deal that paid him $6 million guaranteed in 2017, actually regressed offensively (15 catches, 180 yards, one touchdown) from the season before in Miami (26 receptions, 256 yards, four TDs).

Sims’ $6 million base salary in 2018 becomes fully guaranteed on the third day of the league year. That’s the kind of money reserved for two-way tight ends. The Bears didn’t sign Sims just to block. It’s safe to say Chicago needs better play out of Sims if he’s still on the team next month; the Bears would open up $5,666,666 of salary-cap space if they release Sims before his guarantee kicks in.

Veteran Daniel Brown, who lined up as the Bears’ No. 2 tight end late in the season, is a restricted free agent.

Meanwhile, Adam Shaheen's roster status is not up for the debate, but his performance as a rookie felt incomplete.

The Bears’ second-round pick in 2017, Shaheen finished with only 12 receptions for 127 yards and three touchdowns. He was inactive the final three weeks due to injury.

Still, Shaheen flashed his potential in two games: versus Detroit (four catches, 41 yards and a touchdown) and at Cincinnati (four catches, 44 yards and a touchdown). But the old coaching staff barely played Shaheen after Chicago drafted him from tiny Division II Ashland University. The hope is that new head coach Matt Nagy -- who is set to call the plays on offense -- has a better idea of how to use Shaheen, who is tall and wide enough to box out and post up any linebacker or safety in coverage at 6-foot-6 and 278 pounds. And that he could be the key to a Bears tight end revival.

Nagy comes to Chicago via Kansas City, where the Chiefs made it a point to highlight the tight end position. Travis Kelce led all Kansas City offensive players last season with 83 catches, for 1,038 yards and eight touchdowns.

There’s a strong chance the Bears add one or even multiple tight ends in the offseason to better fit Nagy’s scheme.

Here is a sample of who might be available in the free agency and the draft.

Free agency

Jimmy Graham, Seattle Seahawks: Graham is 31, but he still caught 10 touchdown passes last season. Graham doesn’t appear to be the same player he was with the Saints -- Graham and Pace overlapped in New Orleans -- but he’s still a valuable weapon in the passing game.

Trey Burton, Philadelphia Eagles: Burton (6-foot-3) isn’t a tall target like the 6-foot-7 Graham, but he put up decent numbers (23 catches, 248 yards, five scores) behind Zach Ertz and Brent Celek for the world champion Eagles. Originally undrafted out of Florida, Burton threw a memorable 1-yard touchdown pass to Nick Foles in the Super Bowl. The 26-year-old appears poised for a bigger role offensively in 2018.

Austin Seferian-Jenkins, New York Jets: Seferian-Jenkins has some off-the-field baggage, so this could be a non-starter for the Bears. But at only 25, Seferian-Jenkins is coming off his best NFL season with 50 catches for the Jets.

Draft

Dallas Goedert, South Dakota State: Goedert is probably the best member of an underwhelming 2018 tight-ends class. The Bears did not hesitate to draft players from the FCS level -- and even lower -- last year, so the fact that Goedert played in the Missouri Valley Conference means little. Goedert dominated at that level of competition, with 198 catches for 2,988 yards and 21 touchdowns in his four seasons.

Hayden Hurst, South Carolina: Hurst is another big target at 6-foot-5, 250 pounds. A former baseball player, Hurst initially walked on to the Gamecocks' football team in the summer of 2015. He started to scratch the surface last season, with 44 catches for 559 yards and two touchdowns.