SANTA CLARA, Calif. -- For the San Francisco 49ers to snap their four-game losing streak and beat the Chicago Bears last week, they needed contributions from just about everybody.

But it was no coincidence that in the 33-22 win, some of San Francisco's biggest names and highest-paid players shined brightest. Left tackle Trent Williams was his usual, dominant self. Receiver Deebo Samuel continued his emergence as one of the game's best wideouts. Defensive end Nick Bosa finished with two sacks and stayed on his All-Pro trajectory. Even quarterback Jimmy Garoppolo delivered his best showing of the season.

It was exactly the type of performance the 49ers needed from their most important players. It was also a tiny glimpse into what the Niners will need more of to be in playoff contention. At 3-4, the 49ers' top players will have to stay on the field and produce more consistently.

For the most part this season, that hasn't happened and that's a concerning issue for a team that has become increasingly top heavy over the past few years. Although the 49ers sacrificed defensive tackle DeForest Buckner to salary cap constraints, they handed out top-of-market deals to Garoppolo, Williams, tight end George Kittle, kicker Robbie Gould, linebacker Fred Warner and fullback Kyle Juszczyk. Defensive linemen Arik Armstead and Dee Ford and free safety Jimmie Ward also received sizable deals.

The upshot of those moves is the 49ers have premium players at multiple spots but the so-called "middle class" of the roster has thinned considerably and left a mix of players on rookie deals and veterans on shorter "prove it" type contracts to complement the stars.

"You always want your star players to play like 'A' players every week," coach Kyle Shanahan said. "And then everyone else, you need to play as good as they can, but your star players you need to play like star players every week."

Among the five 49ers with the highest salary-cap numbers this season, only Bosa and Williams have consistently played up to expectations. Samuel is an emerging star who looks the part of a bargain but is playing his way into a large contract of his own.

But some of the other players the Niners expect to lead the way have been inconsistent, injured or a combination of the two.

Garoppolo bears the brunt of that criticism, which is to be expected because of his position but also because of his $26.4 million cap hit. He's missed a game and a half because of a calf injury. When he's been on the field, he's been good at times (against Detroit and Chicago and in the final quarter against Green Bay) but has struggled to string those moments together.

Armstead and Ford count a combined $21.36 million against the cap. While Armstead has been his usual, solid self against the run and still is a strong pass-rusher when he plays inside, he has 18 tackles and one sack with a pressure percentage of 6.9, which is tied for 92nd in the NFL.

Although any production from Ford should be viewed as a win given his recent injury issues, he doesn't play much in an effort to keep him healthy. Ford has a pressure percentage of 10.5% and three sacks but he missed a game with a concussion and has been limited to 16 snaps per game in six contests.

Even Warner, who earned a five-year, $95 million contract extension in July because of his consistency, hasn't played up to his own lofty standards. While Warner has looked more like himself the past two weeks, he's allowed 17 of 20 passes thrown his way to go for completions, according to Pro Football Focus.

"I speak for myself and I hold myself to the highest expectations of anyone," Warner said. "It doesn't matter, media, coaches, my teammates, they're never going to have expectations higher than myself. So, there's always room to grow, always room to do more in my mind."

The injury bug is also having a say in how the 49ers stars are faring. The team's top tight end (Kittle), cornerback (Jason Verrett), running back (Raheem Mostert) and kicker (Gould) have spent time on injured reserve, with Verrett and Mostert lost for the season. Integral youngsters such as defensive tackle Javon Kinlaw and linebacker Dre Greenlaw have missed extended time.

Kittle and Gould are expected to at least return to practice this week, which -- in Kittle's case especially -- would be a big step in getting the Niners back to normal.

"We're missing Kittle out there with his vocal leadership," Bosa said. "It does help to have some guys who are more vocal and will get on other guys about certain things but we have got to work with what we've got."

None of that means the Niners' stars must try to do too much. But it's not lost on them that when things go awry as they already have this season, it's up to them to right the ship.

"There's not some magic potions you can drink or something to do out of my assignment to go and try to make a pick-six to win the game," Warner said. "I'm going to go out there and do my assignment and do it to the best of my ability as hard as I can go. And if I'm doing that on a day-to-day basis, that's when those plays are going to come."