ENGLEWOOD, Colo. -- The Denver Broncos’ offensive woes of 2017 can essentially be boiled down to three major issues: too many turnovers by the quarterbacks in an ill-fitting offense, too little pass protection for those quarterbacks and not enough viable targets for those quarterbacks to throw to.

In the first two weeks of free agency, the team tried to solve two of those issues by signing Case Keenum to be its starting quarterback and by trading for tackle Jared Veldheer. However, that third item -- the whole viable targets thing -- is still largely unaddressed.

In fact, the Broncos decided to let two of the four wide receivers who had touchdown catches last season -- Bennie Fowler and Cody Latimer -- move on in free agency. And of the nine players overall who had at least one touchdown reception last season, four are no longer on the team.

Coach Vance Joseph has called it all “a work in progress" and has said “we’ve got time," but the Broncos made the rather painful discovery last season that Demaryius Thomas and Emmanuel Sanders won’t have enough room to work if the Broncos don’t force defenses to worry about somebody else running pass patterns. Yes, they believe Keenum’s accuracy will fix some of their woes. And yes, they believe a more concerted effort to fit their playcalling to their personnel under offensive coordinator Bill Musgrave will help as well.

“[Keenum] is the right person for our locker room," Joseph said. “He’s a guy who has been through a lot of ups and downs in his football career, and he’s hardened to it. It won’t be too big for him to be a Denver Broncos quarterback, which is a big task. It won’t be too big for him to lead [Thomas] and Emmanuel and those names that we have here. He’s excited about that."

But the Broncos still need a third target, somewhere in the formation, to take some of the attention away from Thomas and Sanders. And unless they believe Carlos Henderson (zero receptions in 2017) and Isaiah McKenzie (four) can take on major roles in 2018, they’ve still got some work to do.

Henderson missed all of 2017 with a fractured thumb he suffered in the preseason and then had a marijuana arrest earlier this offseason. McKenzie was benched multiple times and struggled to carve out playing time on offense.

As a result, beyond Thomas and Sanders, Jordan Taylor is the returning wide receiver with the most catches last season, with just 13. For his part, Keenum said he did his due diligence before he signed with the Broncos and thinks by the time training camp rolls around, the Broncos will have options.

“We did a lot of homework on every team that was a possibility that might want a quarterback," Keenum said. “Every team that we compared them to, the Denver Broncos were by far and away the best option."

However, the issue for the Broncos, especially if Henderson and McKenzie don’t make historically big jumps between their rookie and sophomore seasons, is the market in free agency has been picked fairly clean. Also, history has shown around the league that wide receiver can be one of the most difficult positions for a team to get immediate help in the draft, as players transitioning from college to the pros consistently struggle with the more physical play at the line of scrimmage.

There are still two unsigned wide receivers in free agency who finished 2017 with at least 50 receptions: Kendall Wright and Eric Decker. But Wright visited the Chiefs this past week, and there were some hard feelings when Decker left the Broncos in free agency in 2014.

Of the receivers still available, Jeremy Maclin had 40 receptions last season and Jordan Matthews had three seasons with at least 67 catches with the Eagles before he finished with 25 last season with the Buffalo Bills.

And for the wide receivers in the draft, many personnel evaluators in the league would give consideration to just six or seven among the draft's top 50 players: Alabama’s Calvin Ridley, Texas A&M's Christian Kirk, Maryland’s D.J. Moore, SMU’s Courtland Sutton, LSU’s D.J. Clark, UCLA's Jordan Lasley and Oklahoma State’s James Washington. And those players haven’t faced man coverage like they will in the NFL, which will be the most difficult part of their transition.

The Broncos do believe tight end Jake Butt will help their cause as he moves into his second season. But finding help for Thomas and Sanders just might be the team's biggest piece of unfinished business with the most limited number of potential solutions.