Who will be the third quarterback drafted?

Jameis Winston and Marcus Mariota are the consensus top two draft-eligible quarterbacks this year, but the debate about who will be the third quarterback selected is ongoing.

According to the prospect rankings of Scouts Inc., four quarterbacks are between 87th and 115th -- Bryce Petty, Garrett Grayson, Brett Hundley and Sean Mannion -- and presumably the favorites to be the third quarterback chosen in this year’s NFL draft.

What are the strengths and the question marks of each?

Bryce Petty, Baylor

Strength: Deep throws

Petty led the FBS last season with 20 touchdowns on passes thrown 20 yards or longer. Of those, 13 were thrown 30 yards or longer. Only four other FBS quarterbacks completed more than 13 such throws all season.

Over the past two seasons, Petty was one of three Power 5 quarterbacks to complete at least 60 percent of his throws and have an average pass distance of more than 10 yards.

Question mark: Product of a system?

Petty played 48 snaps -- and threw five passes -- from under center last season. The fewest passes from under center by an NFL quarterback in one season in the past five years (minimum 12 games played) is 24 (Nick Foles, 2013). Petty will likely have to use traditional dropbacks in the NFL more often than he did at Baylor.

Garrett Grayson

Strength: Passing inside pocket

Grayson threw 31 touchdowns and five interceptions from inside the pocket last season. Among FBS players with at least 100 passes, he ranked second in yards per attempt (10.0), third in touchdown-interception differential (plus-26) and first in 20-plus yard plays (60).

Question mark: Can he excel against top competition?

Although Grayson posted eye-opening statistics last season, most of them came against the relatively weak competition of the Mountain West. The Mountain West’s average defensive efficiency was eighth among 10 FBS conferences (better than the Mid-American and Sun Belt conferences).

Grayson faced three opponents with a defensive efficiency in the top 40 in the FBS (Boise State, Utah State, Utah) last season. In those games, he threw three touchdown passes and three interceptions, compared with 29 touchdown passes and four interceptions in the other 10 games. Half of his 26 sacks came against those three opponents.

Brett Hundley

Strength: Extending plays

On third down, Hundley’s 510 scramble yards and 18 scrambles of at least 10 yards trailed only Johnny Manziel among Power 5 players from 2012 to 2014.

Weakness: Can he avoid sacks?

Hundley had issues getting the ball out of his hand throughout his career at UCLA. He was sacked 125 times in his career, 26 more than any other FBS quarterback during this time. Hundley was sacked 75 times when he faced four or fewer rushers, most among Power 5 quarterbacks since the start of 2012.

Sean Mannion

Strength: Blitz recognition

Since the start of 2013, Sean Mannion has thrown 27 of his 52 touchdown passes when facing five or more pass-rushers. His 27 touchdowns trail only Winston during that span among Power 5 quarterbacks.

Weakness: Stats inflated by a stud wide receiver?

Mannion’s statistics across the board regressed from his junior to senior season. In fact, his Total QBR decreased by 26.1 in the two seasons, the second-largest decrease among FBS quarterbacks behind Temple's P.J. Walker.

One factor could have been that Brandin Cooks, the 2013 Biletnikoff Award winner and Mannion’s go-to target during his junior season, was in the NFL in 2014.

Mannion completed 74 percent of his passes with an average of 10.6 yards per attempt when targeting Cooks in his career, but the quarterback completed 63 percent of his passes with an average of 6.9 yards per attempt to all other receivers.

Gruden QB Camp profiles

The sixth season of "Gruden's QB Camp" makes its debut at 7 p.m. ET Tuesday on ESPN2. ESPN Stats & Info has profiled each of the five quarterbacks who will be on this year’s series.

Brett Hundley, UCLA Bruins

Marcus Mariota, Oregon Ducks

Bryce Petty, Baylor Bears

Garrett Grayson, Colorado State Rams

Jameis Winston, Florida State

- Jungkyu Lee, Lauren Poe and Bryan Shalvoy contributed.