Grant Cohn: Five 49ers perched at make-or-break for their careers

For some players, training camp is a nuisance they have to endure without getting hurt. For other players, it's the last chance to fight for a job.

This is about the 'other' players fighting for a job. These are the five 49ers with the most to lose during training camp.

1. CARLOS HYDE

Hyde will be a free agent after next season, and the 49ers probably won't re-sign him next year. They already have his replacement — rookie Joe Williams. The new regime drafted him in the fourth round this year.

Unlike Hyde, Williams is a perfect fit for Kyle Shanahan's outside-zone run game. Williams almost certainly will be the 49ers' starting running back in 2018. The coaches just have to decide when they want to transition from Hyde to Williams — this season or next.

So far during the offseason, the Niners have given Hyde the veteran courtesy. They made him the starter for every practice during OTAs and minicamp. But, that doesn't mean he'll be the starter during the regular season. Hyde will have to play well during the exhibition games to keep his job.

Throughout his career, he has not shown the skills to succeed in the Niners' new running scheme. He's a read-option runner. He lines up behind the quarterback in the shotgun and, if the quarterback doesn't keep the ball, Hyde runs with it up the middle.

The previous regime drafted Hyde to run this play with Colin Kaepernick. Hyde's career average from the shotgun is 4.8 yards per carry. But when the quarterback is under center, Hyde's average plummets to 3.1 yards per carry.

Unfortunately for him, the Niners' new scheme features a quarterback-under-center run game. It requires the running back to have patience so a hole can develop, vision to find the hole and acceleration to burst through it before it closes.

Hyde may not have those qualities. He doesn't run with patience, he doesn't find holes that aren't directly in front of him and he doesn't accelerate quickly. He just tries to break tackles. That's his best quality.

Hyde needs to learn those other things by August. Otherwise, not only could he lose his starting job, the Niners could trade him for a sixth-round pick or a seventh-round pick. Better to get something for him now than nothing for him next year if he leaves in free agency.

2. ERID REID

Reid is another lame duck who will be a free agent in 2018. There is no indication the Niners plan to re-sign him next year.

'As far as I know, there has not been any communication,' Reid said last week, referring to talks between his agent and the team. 'I imagine that if I play well the first half of the season, maybe they will reach out to me. Maybe they will reach out to me before training camp. I don't know.'

I doubt the Niners will open negotiations with Reid's agent before training camp. Reid has to prove himself. This season is an audition.

The new regime already made him switch positions. He used to be a free safety, and his main job was intercepting passes. He wasn't good at that job. Now, he's a strong safety who has to hit like a linebacker and cover tight ends man to man.

Reid may not be good at those jobs, either. He has very little experience in man-to-man coverage and, ever since he suffered his third concussion, he has avoided contact. Reid makes 'business decisions,' as football coaches say. He appears to protect himself to keep himself injury-free and healthy. He doesn't want another concussion to jeopardize career.

If Reid wants to stay in business with the 49ers, he has to stop with the business decisions. As the strong safety, he needs to be the most violent player on the defense. Needs to use his body as a weapon. Think Donte 'Hitner' Whitner from a few seasons ago.

If Reid won't sacrifice his body for the team, the Niners gladly will sacrifice him.

3. VANCE MCDONALD

McDonald is not a lame duck, but he's verging on a dead duck. Trent Baalke signed him to a five-year contract extension last season and the new regime might cut him anyway.

The Niners don't even pretend to like McDonald. They tried to trade him during the draft, but no team wanted him. During practices, they play him mostly with the second-stringers and third-stringers. No veteran courtesy for McDonald.

He's fighting to be the fourth tight end on the depth chart. He already has fallen behind Logan Paulsen, Garrett Celek and rookie George Kittle. Now, McDonald is competing with Blake Bell and undrafted rookie Cole Hikutini. And of those three, the undrafted rookie may have the best chance to make the team.

McDonald's problem is his hands. He drops too many passes. Even in practice, he seems to drop one every day. This has been the case since he entered the league in 2013. Unless he drops zero passes during training camp and preseason, he'll probably be a goner.

4. AARON LYNCH

Lynch has the talent to be the best player on the 49ers defense. But he's fat.

That may sound harsh, but the NFL is harsh, and Lynch is ruining his career because he has no self-control. The last time he spoke to the media — May 24 — he said he gained weight because he didn't eat vegetables and lean meats every day, and he took his wife out to dinner too much.

Oh, so it's his wife's fault he's overweight.

According to a well-placed source, the 49ers want Lynch to weigh no more than 267 pounds by the end of training camp. As of May 24, he weighed between 280 and 290 pounds.

The Niners must not feel confident Lynch can reach their goal, because on June 5 they signed veteran defensive end Elvis Dumervil. Dumervil most likely will take Lynch's job as a third-down pass rusher.

Now, Lynch has to fight just to make the team. And he's competing against someone the new regime is invested in — Pita Taumoepenu, a rookie sixth-round pick.

Lynch better eat his vegetables and lean meats and skip dessert the next five weeks before training camp starts.

5. NAVORRO BOWMAN

Here's what we know:

This offseason, the 49ers signed an expensive inside linebacker — Malcolm Smith. And they drafted another inside linebacker — Rueben Foster — in the first round.

Shortly after the draft, former NFL GM Michael Lombardi reported Bowman is available in a trade if some team is willing to give the Niners anything for him. The 49ers quickly issued a statement saying they were not actively shopping Bowman, but that doesn't mean he's not available.

A few weeks after Lombardi's report, head coach Kyle Shanahan said at a press conference that Bowman would have to compete with Smith and Foster for a starting job. Hmmm.

All of this suggests the Niners are not committed to Bowman long term or short term.

Ordinarily, a player like Bowman, who suffered a torn Achilles tendon less than nine months ago, would skip training camp or practice very little. Bowman doesn't have that luxury. He has to play full speed every day to compete for a job. To show he still belongs in the league.

No 49er has more on the line.

Grant Cohn writes sports columns and the 'Inside the 49ers' blog for The Press Democrat's website. You can reach him at grantcohn@gmail.com.