With signing day in the rearview mirror and spring football just starting, now's a great time to take stock of each of the eight position groups on WSU's roster. Let's go back over to the offense for a unit that is amazingly deep and led by perhaps the best player on the entire roster: The wide receivers.

Looking Back at 2015

In Brief: There was some trepidation heading into the season after the departure of leading receiver Vince Mayle, who took 106 receptions and more than 1,400 yards with him when he departed for the NFL. Those worries turned out to be completely for naught, as Gabe Marks -- a former four-star recruit returning from an injury-plagued redshirt season -- seamlessly replaced Mayle as his quarterback's safety blanket.

You needed a play made at a critical juncture? Take a cue from Marks' Twitter handle: Just @throwitupto9. For a player who saw as many targets as he did, Marks' team-leading catch rate of 70 percent was absurd. He made play after play after play in the biggest moments, none bigger than the game-winning TD against UCLA:

Here it is, your GAME-WINNER! Falk to Marks, 21 yards! #GoCougs https://t.co/rGV9770r36

— WSU Cougar Football (@wsucougfb) November 15, 2015

Dom Williams replaced Mayle as the big-play threat, and he did not disappoint. He continued to have a few issues with the dropsies, but he also was awesome in the clutch, and he and Marks made for a devastating tandem on the outside.

Because of the targets that went to Marks -- way more targets than Isiah Myers attracted the year before at Z -- the Y position took a little bit more of a backseat with Falk at the helm. River Cracraft had a year that was only slightly more productive than his freshman season, but he was still awesome when called upon.

Meanwhile, Robert Lewis brought some much needed production to H, which had been woefully underutilized in Mike Leach's first three seasons. He caught virtually the same number of balls, but he proved to be harder to bring down than in his freshman year, accumulating 120 more yards. He also might give Marks a run for his money as the toughest receiver on the field; the work he does as a blocker is amazing considering his size (5-foot-9, 170 pounds).

Newcomers Tavares Martin Jr., Ky Priester and Kyle Sweet each found roles -- Martin backing up Marks and returning kicks, Priester using his athleticism to become something of a screen game specialist, and Sweet showing elusiveness on the inside. All showed enough to have fans incredibly excited about their futures.

John Thompson and Tyler Baker both were reliable options as reserves.

Looking Ahead to 2016

Williams departs, taking his big-play ability with him, but everyone else of note returns -- including Marks, who many thought might take his degree and head off to try his hand at impressing NFL scouts.

But when Marks announced he had some unfinished business he wanted to take care of, this instantly became one of the -- if not the -- scariest receiving units in all of the Pac-12.

At the top, Marks is a legitimate Biletnikoff Award candidate. He was a semifinalist for the award a year ago before being trimmed from the list -- something that didn't sit well with him. And that's part of what makes this group so exciting: These guys have an absolute lion leading them, a man who displays such incredible grit and toughness, his teammates can't help but follow his example.

The odds-on favorite to replace Williams opposite Marks is Martin. Although he backed up Marks a year ago as a true freshman, he fits the profile of what X has become in the Air Raid under Leach at WSU: Long-striding speedsters who can take the top off a defense. Still, Martin only caught 16 passes last season (seems like more, doesn't it?), which means a seamless insertion is far from certain.

Priester got lots of snaps at X in 2015, but he was lining up at Y at the first spring practice -- something of a surprise, given that he seemed to have the speed and body type to potentially dominate on the outside. However, it's that speed and strength that makes him a potentially intriguing piece on the inside. He's already demonstrated his ability to run through contact, something that could be a big asset inside where there are more bodies.

Lewis will continue to do what he does at H, the position that typically draws the fewest targets. I'd also expect Sweet to back him up there if Priester indeed sticks at Y.

Among the newcomers, Floridian Isaiah Johnson probably is positioned to make the most immediate contribution. At 6-3 and 214 pounds, he already looks the part and is enrolled and taking part in spring drills. I'd expect him to head for X. C.J. Dimry isn't technically a newcomer, but after redshirting last year, the 6-foot-5 junior college transfer could also be a factor at X, potentially replacing Williams' jump ball prowess in the end zone.

Other freshman who will be showing up this summer include Renard Bell (5-10/165), Dezmon Patmon (6-4/202) and Grant Porter (6-2/185); all will get a shot to play right away, with Bell profiling on the inside, and Patmon and Porter looking like outside receivers.

Also potentially contributing on the outside will be Kaleb Fossum, a walk-on whom the coaches like. He was running with the second team as spring practices got underway.

2017 Recruiting Outlook

Even with so many receivers on the roster, this always is a position WSU will recruit heavily -- with four receivers on the field on virtually every play, the Cougars rotate players heavily. According to Rivals, the Cougars have 10 offers out to receivers, perhaps indicating that WSU will cap its WR commits at three after taking four in the last cycle:

Bell is thought to be particularly interested; he's got offers from Iowa, Nebraska and Colorado so far. Isaiah Hodgins also is a kid at which the Cougs have a realistic shot. Here's his highlight video from his junior season:

If you're looking for the sickest highlights, that's probably four-star Tyjon Lindsey: