METAIRIE, La. -- Sean Payton gave one of the best pieces of fantasy advice in recent memory two years ago, when he said of rookie receiver Michael Thomas: "I don't follow fantasy football, but shoot, I'd try to have him."

Unfortunately, the New Orleans Saints coach isn't doing any favors in that department this summer.

Outside of Thomas, the pecking order for the rest of the Saints' wide receiver corps is one of the hardest to pin down in the entire NFL. Their preseason usage has offered little guidance. And Payton said after Saturday's win at the Los Angeles Chargers:

"That depth chart is like written in chalk. It's not permanent ink."

Newcomer Cameron Meredith has great potential in New Orleans' offense if he returns to full health after signing as a restricted free agent. And he appears to be on the mend from the major knee injury that wiped out his 2017 season with the Chicago Bears exactly one year ago on Aug. 27. But he remains a work in progress after missing a couple weeks with an unspecified ailment early in camp.

Meredith has zero catches in 48 preseason snaps -- including a dropped pass that turned into an interception two weeks ago. And he played mostly with the backups this past Saturday.

Veteran Ted Ginn Jr. was underrated as the Saints' steady No. 2 receiver last season and could be again in 2018. He was even better in the playoffs (12 catches for 187 yards and a touchdown in two games) than he was in the regular season (53-787-4). But the 33-year-old now has more competition for that "No. 2" role. And it didn't help his stock when Payton called him out for running the wrong route twice in the second preseason game.

Rookie third-round draft pick Tre'Quan Smith, meanwhile, has been one of the most exciting players in camp -- routinely making splash plays in both practices and games. The 6-foot-2, 210-pounder from Central Florida has shown an enticing combination of size, speed, hands and big-play ability, and he leads the Saints in catches (11), yards (147) and touchdowns (1) this preseason. However, Smith has been limited to mostly just playing the "Z" position as he continues to work on assignments and alignments.

Then there is second-year receiver Austin Carr, who felt like a forgotten man for much of the summer -- until he played with the starters as the primary slot receiver ahead of Meredith on Saturday and caught three passes for 38 yards.

All of that leaves little room for third-year pro Tommylee Lewis (who appears to be on the verge of losing his kick-return job to newcomer Brandon Tate), veteran Michael Floyd or impressive undrafted rookie Keith Kirkwood, among others.

"Listen, you wish you could keep seven or eight, right?" said Saints quarterback Drew Brees, ever the diplomat. "I feel like I've got some pretty good chemistry with a lot of guys. Wish we could keep 'em all."

But if you're expecting to hear the old cliché of "This is a good problem for the Saints to have" -- well, not so fast.

Obviously the quantity of candidates is nice. But the Saints need to figure out which ones they can really count on.

Last season New Orleans ranked second in the NFL in total offense (391.2 yards per game) and fifth in passing offense (261.8 yards per game) while Brees set the NFL record for completion percentage (72.0). But the Saints ranked a stunning 19th in the league in third-down conversion rate (37.6 percent) -- a category where they have routinely led the league during the Payton-Brees era.

The Saints only had two receivers or tight ends with more than 23 receptions last season (Thomas 104, Ginn 53). That's a big reason why they went out and signed Meredith and veteran tight end Benjamin Watson in free agency before drafting Smith.

So here's the fantasy football question that none of us -- including Payton -- can really answer right now: Which one of these guys do you want to draft?

Ginn is probably the best bet to put up the same kind of numbers he did last season. But Meredith and Smith both offer bigger upside.

Meredith's potential is mostly tied to his health. The 6-3, 207-pounder was poised to be Chicago's No. 1 receiver last summer before he tore his ACL and MCL. Undrafted out of Illinois State in 2015, he burst onto the scene with 66 catches for 888 yards and four TDs in just 14 games in 2016.

But Meredith's injury was so severe that the Bears weren't even willing to offer him a one-year, $2.9 million tender to keep other teams from pursuing him as a free agent. And they declined their option to match the Saints' two-year, $9.5 million offer.

The good news is that Meredith's knee seems to have held up well so far. Unfortunately, the results haven't shown up yet in practices or games. But Meredith, Payton and Brees have all spoken positively about his trajectory.

"I'm encouraged with his progress, and I'm encouraged with his conditioning level. It's gotten better," Payton said last week.

The Saints will be patient with Meredith. They didn't just sign him to be a breakout star in Week 1 of the 2018 season.

Smith, on the other hand, has shown great results almost every day in practice. No one is making more big plays down the field, week after week. But at the same time, Payton and Smith have both been pretty blunt about how much he still needs to learn.

Payton said it might be a case where the Saints have to "keep giving him the reps at what we think he's going to be doing in the game and reduce some of the variables."

Payton stopped short of comparing Smith's rookie-year potential to Thomas' potential in 2016 (when he caught 92 passes for 1,137 yards and nine touchdowns). But Payton did say he's encouraged by how bright Smith is, along with his his strong hands, his running ability and his blocking ability.

Saints receivers coach Curtis Johnson also praised Smith's intelligence, saying, "For a young kid, he's picking this thing up pretty well."

And Smith has talked passionately about wanting to become both a great receiver and a great student. He compared it to being back in school and being so much more confident when you actually know the answers while taking a test.

"Because me being at one position, I'm holding myself back," Smith said. "But if I can get in my playbook more and learn more, I can be in different positions and give me an opportunity to play more.

"When I don't have to think about it, it's a much higher possibility I can be a playmaker."