SANTA CLARA, Calif. -- It would be a bit of a stretch to say the personality of the San Francisco 49ers will be ruined by the loss of their fullback.

However, there is no discounting it; the loss of the versatile, valuable Bruce Miller will hurt the 49ers.

The team is expecting Miller will miss the rest of the season with a broken scapula. He suffered it in the fourth quarter of the win at Tampa Bay on Sunday. After the game, Miller said he didn't think it was serious. Monday told a different story.

“Very significant” 49ers' coach Jim Harbaugh said Monday of Miller's loss. “He does so many things in the protection and the run game. Receiving out of the backfield. He is a multi-talented, multi-use player. Special teams contributor on two, three phases, so it's a loss.”

The 49ers are one of the few teams to use a fullback in a major role. They are still mulling what to do. The top in-house options are backup running back Anthony Dixon. He is athletic, versatile and tough. He could be the first player the 49ers look at.

Another interesting possibility is reserve inside linebacker Michael Wilhoite. A special teams maven and a strong injury replacement for the great Patrick Willis earlier in the season, Wilhoite played some fullback in the training camp. He is more than willing to play offense while Miller is out.

Harbaugh said Monday the team was bringing in Owen Marecic for a look. He played for Harbaugh at Stanford and he spent a short time with the 49ers earlier this season. There were indications Monday evening that the 49ers weren't sure if Marecic was up to playing a huge role. So, replacing Miller is still a work in progress.

He played nearly 60 percent of the snaps. His presence will be missed.

“That is kind of a big under the radar loss,” ESPN analyst Matt Williamson said. “He is a bit of a fullback/tight end tweener to me, but a real hammer as a blocker. They really stress physicality and want to use a very wide variety of personnel groupings, which he was perfect for. I don't know what they plan to do as a backup plan, but lead blocking fullbacks generally are not hard to find, but few do as much as him.”

It would be overstating it a bit to say the loss of a fullback will devastate any NFL offense in today's game. But the 49ers liked what Miller brought, so it will be an adjustment.

The good thing is receiver Michael Crabtree and Mario Manningham are playing after being out with injuries. So, the 49ers will likely do more three-receiver sets. Expect to see a lot of double tight end sets as well.

There are plenty of things the 49ers can do to mask this loss, but the point is they were very comfortable with Miller being a big part of the offense. In the meantime, they will have to hope his replacement -- whether it is Dixon or Wilhoite or someone else -- can raise his game when he is on the field. Miller was an enthusiastic player who fit with this group. His energy will be missed as well.

The Miller loss also means the 49ers will go the entire season without having their top 11 offensive players on the field for a snap. The 49ers have adjusted along the way and now will have to do it again without their feisty backfield security blanket for the stretch run.