Every offseason, fans get hyped for the third preseason game as it’s the first chance to see their starters play a majority of the game. Immediately after the third week, fans shift their attention and focus to the regular season opener.

However, I would argue that the final preseason game is the most important, as it determines the fate of players sitting in the roster bubble. Heading into Thursday’s preseason finale against the Chargers, these are the 49ers’ players that need to step up their performance, otherwise they will be cleaning out their lockers soon.

RB Joe Williams

“Who’s Joe?” — was the sentiment among a majority of the 49ers’ fan base after seeing running back Alfred Morris light up the Colts’ defense last week. After Morris’ stellar play, it’s pretty clear that running backs Jerick McKinnon, Matt Breida and Morris are locks to make the final 53-man roster.

With Kyle Shanahan hinting at keeping four tailbacks on the final roster, that final spot is likely down to three players. Raheem Mostert, Jeremy McNichols and Joe Williams will be the ones in consideration.

McNichols has not shown enough through three weeks, so he’s probably out of the running already. Due to his versatility on both special teams and offense, Mostert is probably a safe bet as the fourth tailback — heading into Thursday.

Williams is the one player that can likely change his fate on Thursday with an breakout performance — if he gets a chance to play. He missed last Saturday’s action in Indianapolis (broken rib) and his status is up in the air for Thursday. Per Shanahan, “Joe didn’t practice today [Tuesday]. We’ll see how he is tomorrow [Wednesday].”

The ex-Utah running back has been underwhelming after returning from his redshirt rookie season. In two preseason games, Williams has rushed for 45 yards on 19 carries — a number that’s just not good enough in the NFL. Shanahan may be willing to keep Williams on the 53-man roster if he sees flashes of potential from the tailback on Thursday.

WR Aaron Burbridge

This season’s 49ers’ wide receivers group is probably the most talented they’ve had in years, causing good headaches for the front office. Returning receivers Pierre Garçon, Trent Taylor and Marquise Goodwin are locks to make the roster. Assuming Shanahan keeps six wideouts, there’s three spots for Dante Pettis, Richie James, Kendrick Bourne and Aaron Burbridge.

The two rookies, Pettis and James, are also safe bets to be in the lineup for Week 1, so the competition is between Bourne and Burbridge. With the ex-Eastern Washington star, you get speed and a higher ceiling at the receiver position, where as Burbridge gives you a player that can be a core special teamer and a middling wideout.

This entire preseason, Burbridge has only made one catch for 16 yards, where as Bourne has six receptions for 58 yards. The ex-Spartan is currently on the outside looking in, but there’s a slim chance that he can earn a roster spot on Thursday.

S Tyvis Powell

The starting safeties for the 49ers will be Jaquiski Tartt and Adrian Colbert, there’s absolutely no doubt in that. Rookie defensive back D.J. Reed has been the primary backup free safety, along with nickel corner, so he is likely the third safety to make the roster.

With safety Chanceller James being released earlier on Monday, there’s a strong chance that Tyvis Powell makes the final 53-man roster. In three preseason games, Powell has seven tackles and two passes defensed. After starting the offseason at corner, the ex-Buckeye has shifted to safety and been a strong backup in his role.

During Tuesday’s press conference, Shanahan added “He showed it wasn’t too big for him, he did a good job, and he should get some more reps in this game, also.” Looks like Powell made the most his opportunity last week and can lock up a roster spot with a solid performance on Thursday.