The NFL Scouting Combine is under way, so there is no better time than now to start looking at players who will be working out in Indianapolis.

Today we investigate five who could hurt their stock over the weekend.

RELATED: Five who could help their stock | Farrell Mock Draft | Gorney Mock Draft

Recruiting: In May before his senior season, Peppers committed to Michigan over Penn State and others. At one point, Stanford was the front-runner, but the Wolverines were his childhood favorite. This season, Peppers was third on the Wolverines with 72 tackles (16 for loss) and four sacks. He also had an interception and a forced fumble. Peppers was used on offense and special teams as well.

No question: Peppers is a team leader who is incredibly versatile, so he can be utilized at safety or outside linebacker. The former five-star could also contribute on special teams because of his playmaking ability.

Question: At the NFL level, does Peppers have the ball skills and closing speed to play safety or would he be forced to be an undersized outside linebacker? He only had one interception and one forced fumble in his college career, so is that a sign teams didn’t throw his way or he’s not as big of a playmaker as first thought?

Farrell’s take: This combine is huge for Peppers because if he doesn’t knock it out of the park, he could slide big time without a true position. Many expect him to be a combine freak, but I’m not sure if he will be. If he runs an average 40 time and looks just good and not great in drills, he could be in trouble.

Recruiting: In January, planning to be early enrollee, Walker flipped his pledge from Alabama to Florida State. Coach Jeremy Pruitt’s decision to leave the Crimson Tide for the Seminoles played a big role in Walker’s decision. Pruitt happens to be back on the Alabama staff. This season Walker finished with 68 tackles (21.5 for loss) along with 16 sacks. He also had three forced fumbles and two fumble recoveries.

No question: Walker finished second in the NCAA in sacks, 0.5 sacks behind Boston College’s Harold Landry, and he was incredibly productive getting into the backfield and causing havoc off the edge. He also dealt with double teams often and had no real issues beating them.

Question: Walker needs to show consistently that he’s going 100 percent and there are also questions about his foot speed, so he runs the risk of not testing incredibly well at the combine.

Farrell’s take: Walker is a terrific football player but not a great athlete, so he could fall flat at the combine and slide further. He’s not mentioned as a first-rounder despite his amazing season and he could go from second round to third round with a bad performance.

Recruiting: Jackson picked USC on National Signing Day with UCLA, Florida and LSU being his other finalists. Tennessee was also a major player late in his recruitment and Oklahoma and others were considered, since Jackson is originally from the Midwest. This season, Jackson had 55 tackles, a team-high five interceptions and two fumble recoveries. He also returned two kicks and two punts for touchdowns.

No question: Jackson is one of the most dynamic players in college football, he’s exciting with the ball in his hands on special teams and he could be used in certain offensive packages as well. He’s an athletic cornerback who can go up and get the ball and no receiver can run by him.

Question: There is no getting around the fact that Jackson is undersized and not incredibly strong especially compared to bigger NFL receivers. Despite his athleticism, will Jackson be exploited on the outside?

Farrell’s take: Jackson needs to bust off a sub 4.4 40-yard dash or he could slide into the middle of round two or later. Everyone expects him to be one of the fastest in the 40, so if he has an off day, his size will be illuminated even further.

Recruiting: Baker picked Washington over UCLA the night before National Signing Day. He had previously been committed to Oregon. This season Baker led the Huskies with 71 tackles (10 for loss) with three sacks. He also had two interceptions and a forced fumble.

No question: Baker is a fearless safety who is a hard-nosed kid that plays bigger than his size and he has terrific productivity from his position. He’ll fly in there and hit guys across the middle and he has the speed to cover deep.

Question: There will be questions about his size. He’s listed by Washington as 5-foot-10 and 192 pounds, so can someone play safety in the NFL at that size? If he doesn’t blow out the combine workouts and if his measurements are a tad off, Baker runs the risk of sliding in the draft.

Farrell’s take: Baker isn’t as fast as Jackson and he lacks size for a safety, so he’d better surprise in testing and really kill it in drills. For a smaller guy, the combine setting can probably only hurt unless he tests off the charts.

Recruiting: King was committed to Central Michigan and Ball State before finally flipping to Iowa about a week before National Signing Day. Neither Michigan nor Michigan State offered the three-star standout. King finished with 58 tackles, three interceptions, a fumble recovery and a forced fumble this season. He also contributed on special teams.

No question: King has tremendous ball skills. He had eight interceptions and 13 pass deflections two seasons ago. He had 13 career picks with the Hawkeyes. He can also be a valuable asset on special teams.

Question mark: On the pro level, how fast and athletic is King and can he keep up with NFL receivers on the outside? If not, would a move to safety plummet his draft stock?

Farrell’s take: King isn’t a burner and some already have him slotted as a potential safety because of it. But what if he runs a slow time for a safety? Not only will he lose the coveted cornerback title but could slide amongst the safeties as well. He needs to surprise everyone with a really good time and elite athleticism.