The Boston Celtics are entering the 2022-23 season with title or bust expectations. After making it all the way to the 2022 NBA Finals, despite a dreadful 18-21 start to the season, the Celtics put together a quiet offseason, but it was one in which they clearly emerged as a better team than they were last season.

The Celtics have arguably the deepest roster in the league heading into the season. Star forwards Jayson Tatum and Jaylen Brown will draw most of the attention, but Boston didn't lose any key members of their rotation from last season, and will likely see Malcolm Brogdon, Blake Griffin, and Sam Hauser all be added to an already deep lineup.

Boston will have to see if they can withstand the blow of losing their head coach Ime Udoka for the upcoming season, but considering the talent on their roster, they should still be a shoo-in for the playoffs. Heading into the season, though, it's clear the C's success could depend heavily on whether or not this X-factor can make an impact for his team, so let's see who this player is and why he's so important to the Celtics upcoming season.

Celtics X-factor: Robert Williams

Robert Williams entered the 2021-22 season as the Celtics starting center, and he quickly became one of the most dominant two-way players in the game. Williams anchored the paint at both ends of the court, and was particularly efficient on defense, where he recorded a number of highlight reel blocks that many other players in the league would be proud to have tied to their name.

Boston really began to take off last season when they switched Williams onto the opposing teams' worst shooter on defense, and allowed him to play a free safety role of sorts in the paint. Williams was quick enough to rotate over to the paint if one of his teammates got beat, while also being long enough to get back to the perimeter if the ball got kicked out to his man.

The C's defense held up with Williams operating at less than 100 percent during the playoffs, and he very nearly helped them pull out a title. But when he was fully healthy last season, it was very tough to score points on a consistent basis against Boston. It still was throughout the playoffs, but Williams was clearly struggling with a knee injury for much of the postseason.

Those injury concerns have followed him into the 2022-23 season, where Williams will miss the first two months of the season after undergoing surgery on his knee right before the start of training camp. The hope was that rest would be enough for Williams to heal up this offseason, but this unexpected surgery is a roadblock for Williams and his team.

There are a few main reasons why Williams is the X-factor for Boston this season. For starters, their defense without him on the court is drastically different than when he's on it. Adding Malcolm Brogdon, another long, versatile defender should help, but this will put a lot more pressure on veteran big man Al Horford to step up early in the season, which isn't ideal.

There's also a chance that Williams' timeline gets delayed along the way. This surgery was unexpected, and while he will hopefully be able to shake this knee injury with this surgery, we have seen cases where that doesn't happen. If Williams can't return to the court as soon as expected, that's going to put the C's in an even bigger hole than initially expected.

The Celtics don't necessarily rely on Williams to win them games, but they can't reach their full potential when he's not on the court. He offers a vertical presence on both ends of the floor that no one else on this team can, and that forces their opponents into a corner that they often can't escape.

Tatum, Brown, and the rest of the C's core should be able to guide Boston through the start of the season while Williams is on the sideline. They did as much late last season when Williams tore his meniscus, which caused him to miss the start of the postseason. But Boston has serious title expectations this season, and Williams is the key to reaching them this season.

If Williams can be good to go for playoff time, Boston likely won't mind him missing the start of the season. But the difference between winning and losing a title could fall on Williams' shoulders this season. If he can return to the court and play like himself, it's tough to see anyone beating the Celtics this season. But if he can't, the Celtics could be left searching for answers after coming up short of a title yet again.