SANTA CLARA, Calif. -- Over the past two seasons, San Francisco 49ers tight end George Kittle has loudly proclaimed his return from injury with a big performance in prime time.

Last year, Kittle came back from knee and ankle injuries by posting six catches on six targets for 129 yards with a touchdown in a win against the Green Bay Packers. Last week, he returned from a sprained left knee and had 15 catches on 15 targets for 183 yards and a score.

"Kittle played his butt off," coach Kyle Shanahan said. "Didn't realize that out there that he had that many catches and stuff, but when I think back to it, it makes sense. He got open every time we went to him and did a hell of a job in the game."

Kittle's heavily-anticipated return to the lineup in Week 4 wasn't enough to spark the 49ers to a victory against the Philadelphia Eagles. In fact, Sunday night was Kittle's fourth career game with nine or more catches and the 49ers have lost all four of them. That is by no means a knock on Kittle, but it does illustrate how important it is for the Niners to get back to full strength so they can attack defenses in multiple ways.

The good news? After getting Kittle and receiver Deebo Samuel back last week, more help is on the way. Quarterback Jimmy Garoppolo (high right ankle sprain) and running back Raheem Mostert (sprained knee) are the next pieces the 49ers anticipate returning to the fold.

Of the utmost importance is getting Garoppolo back. He's been out since halftime of the Week 2 win against the New York Jets and though there's hope for him to play as soon as Sunday against the Miami Dolphins (4:05 p.m. ET, Fox), that remains uncertain after he practiced on a limited basis Wednesday. Although the 49ers cruised to wins against the Jets and New York Giants, backup Nick Mullens struggled mightily against the Eagles, turning it over three times on his way to being benched in favor of C.J. Beathard.

And while getting Garoppolo back should be a boon for the offense, Mostert's impending return -- he also was limited Wednesday though Shanahan isn't as optimistic about him playing this week -- is almost as important. Backups Jerick McKinnon and Jeff Wilson Jr. have done well in Mostert's stead but the offense has undoubtedly missed Mostert's explosiveness and willingness to hit the hole at top speed.

The 49ers rank 11th in rushing yards per game (128.5) and eighth in yards per carry (4.72). But those numbers don't tell the full story for a run game that has hit on some big plays but has failed to consistently keep the Niners in favorable down-and-distances.

The Niners have gained 173 of their 514 rushing yards on three plays, Mostert's 80-yard touchdown, McKinnon's 55-yard scamper and receiver Brandon Aiyuk's 38-yard touchdown. Aside from those big plays, Niners running backs have struggled to find room to run consistently, averaging 4.33 yards per carry on 95 attempts. Subtract Mostert's 80-yard score and that average dips to 3.5 yards per carry.

Of more concern is the fact NFL Next Gen Stats has the Niners down for 72 unsuccessful rushing plays (defined by percentage of yards gained toward a first down), which is the third-most in the league, and 21 negative rushing attempts, the most in the NFL.

Given that everything the 49ers do offensively spins off of a successful run game, getting Mostert back and finding more consistency in the run game should be the Niners' top priority.

"Everything's tied together," Shanahan said. "When you run the ball real well, play action is a lot easier. When you run the ball real well, dropping back is a lot easier. We ran the ball extremely well last year, and I think that's why it's hard to find a category in football that we weren't in the top five last year. ... When you're not running the ball well, I think it's very hard to be successful. I don't think we're running it horribly, but we're not close to what our standard is right now and that's got to improve for us to get better everywhere else."

Scoring is as important as ever this season. The 49ers are averaging 26.8 points per game, 11th in the NFL, which is down from the 29.94 points they averaged last season that was good for second in the league. Through four weeks, teams have averaged a combined 51.3 points per game, the highest total through four weeks in a season since the AFL-NFL merger in 1970. Put in perspective, the Niners' average from last season would currently rank ninth in the league.

Although the 49ers defense has also been hit hard by injury, that unit hasn't showed too much of a drop off. But with defensive end Nick Bosa (torn ACL) lost for the season, cornerback Richard Sherman (calf) and edge rusher Dee Ford (back) out with injuries and the schedule about to get more difficult, a defensive regression is probably forthcoming.

All of which puts the onus on the offense to pick up the slack. The sooner it gets back to full strength, the better the chances of that happening.

"It's going to be really exciting," McKinnon said. "We haven't had everybody together at one time. Guys here and there are hurt. Myself the last two years and we have got some guys dinged up right now but the good thing about it is in a couple weeks, we're gonna get everybody back and it's definitely going to be exciting and teams are going to have their hands full for sure."