ORCHARD PARK, N.Y. -- The Buffalo Bills had one of the most top-heavy offensive backfields in the NFL last season, simplifying life for fantasy football teams that employed LeSean McCoy.

McCoy is still the unquestioned top running back in Buffalo, but a potentially deeper supporting cast could cut into his value as fantasy drafts take place in advance of NFL opening night next Thursday.

The Bills leaned on McCoy more than ever last season. He accounted for 32.8 percent of the Bills' total yards from scrimmage, the second-highest percentage among NFL running backs only to the Los Angeles Rams' Todd Gurley (36.2 percent). McCoy played in 68.2 percent of offensive snaps, the seventh-highest rate among NFL running backs, and touched the ball on 44.6 percent of the Bills’ total offensive touches, second only to Pittsburgh's Le'Veon Bell (49.5 percent) among all runners.

Buffalo was forced to rely on McCoy, in part, because of a lack of capable running backs behind him. McCoy was buttressed in his first season in Buffalo by Karlos Williams (5.56 yards per carry in 2015) and Mike Gillislee (5.68 yards per carry) before off-field issues led to Williams' release in 2016. Even so, Gillislee carried the load behind McCoy in 2016, averaging 5.71 yards per carry before he signed a restricted free-agent deal with the New England Patriots in the 2017 offseason.

The Bills chose hybrid fullback/running back Mike Tolbert, then 31, as McCoy's primary backup last season over Jonathan Williams, who was released during final cuts. Tolbert, who suffered a midseason hamstring injury and saw his playing time reduced in favor of Travaris Cadet, finished last season with 325 yards from scrimmage. Only three teams' No. 2 running backs -- the Steelers', Rams' and Kansas City Chiefs' -- were less productive.

The situation behind McCoy has potential to improve this season. Buffalo did not re-sign Tolbert and instead signed Chris Ivory, who generally underperformed with the Jacksonville Jaguars but produced more yards per touch (4.9) last season than Tolbert (4.1) while gaining first downs at a higher rate (17.3 percent) than Tolbert (13.3 percent).

In addition, the Bills will return Marcus Murphy after he was promoted from the practice squad for the final game of the 2017 regular season. Murphy ran seven times for 41 yards in that game, including a 25-yard touchdown, and has averaged 6.0 yards per carry on 22 rushes this preseason.

"[He’s] done everything right; this guy is a young player, but he practices the right way, he prepares the right way," Bills offensive coordinator Brian Daboll, who joined the team this offseason, said last week. "Obviously, he’s had a good training camp, but the success that he’s had in these first couple [preseason] games is a product of what kind of kid he is, how hard he works, the preparation [and the fact that] he’s serious, how he finishes in practice. There’s numerous clips out there [showing that] he just does the right thing. He’s very dependable, and hopefully he just continues to get better."

The continued emergence of Murphy this preseason should secure him at least the third spot on the depth chart behind McCoy and Ivory, who projects as Buffalo's top back in short-yardage situations. That will likely leave only one more spot on the 53-man roster. Taiwan Jones, who made his mark on special teams early last season before a season-ending arm injury, looks to have the edge given those roles, including as a kick returner and gunner on punts. That could leave Cadet and undrafted rookie Keith Ford on the outside of the roster picture.

While the Bills appear to be better positioned in their backfield than last season, their potentially improved depth could present more questions for fantasy players, including:

• Will Ivory "poach" goal-line carries from McCoy? This is a concern to McCoy's fantasy owners because McCoy could potentially lose points if Ivory scores touchdowns. McCoy received 76.2 percent of the Bills' red zone snaps last season, the fourth-highest rate among NFL running backs, and took 73.1 percent of snaps within 3 yards of the goal line, 10th-most among NFL runners. Five of McCoy's eight touchdowns last season came from the red zone and one came within 3 yards of the goal line.

• Will either Ivory or Murphy receive enough consistent playing time to warrant fantasy consideration? Murphy, 26, presents upside as a consistent No. 2 option behind McCoy if Ivory, 30, is not efficient at this point in his career. However, Ivory showed some burst in rushing three times for 31 yards in the Bills' preseason game last Sunday against the Cincinnati Bengals. If Ivory and Murphy split snaps behind McCoy this season, it could diminish the fantasy value of both. Daboll hinted at such a time-sharing arrangement last week when he said, "There’s roles for everybody that is a good player. I’ve been part of teams that have four, five running backs active in a game. Everybody has a different skill set, whether it’s size, speed, quickness, pass protection. It’s good to have a variety of skill guys, particularly at that position that can do different things." Daboll has a background in a Patriots system that is notorious among fantasy owners to use running backs in roles specific to each week's game plan, creating a unpredictability that fantasy players view as a risk.

• Will McCoy stay healthy and stay on the field? McCoy, 30, has appeared "quicker, faster and more powerful" this year than last season, coach Sean McDermott said during training camp. While his age is a looming concern that has yet to present itself on the field, McCoy must also avoid injuries in the way he did last season. Hamstring injuries cut into his playing time in both of his first two seasons in Buffalo. There is also an ongoing police investigation into a July home invasion at an Atlanta-area house owned by McCoy in which McCoy has neither been named as a suspect nor been publicly exonerated by police. The ongoing police and NFL review of the case could affect his availability until official word says otherwise.