Every year, there are a group of players who enter the playoffs with more to prove than others.

Even though there are still eight "seeding" games to be played before this season's playoffs, we have seen enough to know which players will have the spotlight on them in the postseason.

Four names at the top of the list: Toronto Raptors forward Pascal Siakam, Houston Rockets guard Russell Westbrook, Philadelphia 76ers guard Ben Simmons and Milwaukee Bucks forward Giannis Antetokounmpo, each of whom have something to prove for very different reasons.

Let's take a closer look.

Pascal Siakam, Toronto Raptors

Following Toronto's most recent loss to Milwaukee, our Micah Adams wrote about whether or not Siakam is ready to be a true No. 1 option on a championship team.

You can read what he had to say here, but the gist of it is that Siakam hasn't been able to elevate his game to the same level as other stars in head-to-head matchups this season. He struggled against Giannis Antetokounmpo on a couple of occasions, as well as the likes of Anthony Davis, Kawhi Leonard, James Harden and Luka Doncic.

Now, those are some of the best players in the league. In the case of Antetokounmpo, Davis and Leonard, some of the best defenders, too. But if the Raptors are going to make another deep postseason run, they'll need their best player to be the best player on the court in numerous series. It might not be much of a factor in the first round — neither the Brooklyn Nets nor Orlando Magic as we currently know them pose as much of a threat — but the Raptors could face either the Boston Celtics or Philadelphia 76ers in the second round, followed by the Milwaukee Bucks or Miami Heat in the Eastern Conference Finals.

In which case, they'd have to go through some combination of Jayson Tatum, Joel Embiid, Ben Simmons, Jimmy Butler and, of course, Antetokounmpo to make the Finals again.

Realistically speaking, I'm not sure anyone is expecting Siakam to get the better of Antetokounmpo over the course of a series. (Leonard and LeBron James might be the only players in the league who can). As for the others, Siakam has graduated to a point where he should be expected to hold his own against Tatum, Embiid, Simmons or Butler. He just hasn't done it enough times this season to confidently say that he will for an entire series, which is why all eyes will be on him in the playoffs.

Russell Westbrook, Houston Rockets

Here are Westbrook's stats from his last three playoff appearances:

• 2016-17: 37.4 points, 11.6 rebounds, 10.8 assists and 2.4 steals per game
• 2017-18: 29.3 points, 12.0 rebounds, 7.5 assists and 1.5 steals per game
• 2018-19: 22.8 points, 10.6 assists, 8.8 rebounds and 1.0 steals per game

Impressive, right?

Now, for the shooting splits:

• 2016-17: .388/.265/.800
• 2017-18: .398/.357/.825
• 2018-19: .360/.324/.885

Outside of his free throw shooting ... not so impressive.

It doesn't help that the last time Westbrook got out of the first round was 2015-16. He lost to the Rockets in five games in 2016-17, the Utah Jazz in six games in 2017-18 and the Portland Trail Blazers in five games in 2018-19. The Oklahoma City Thunder weren't favoured against the Rockets, but they were against both the Jazz and Trail Blazers.

Also not helping? Westbrook got outplayed by another guard in each of those series: James Harden in 2017, albeit not quite to the same extent as Donovan Mitchell in 2018 and Damian Lillard in 2019.

Now a member of the Rockets, Houston is hoping Westbrook can be a more efficient scorer in its system. Westbrook didn't get off to the best of starts this season, but he was playing some of the best basketball of his career prior to the NBA season being suspended. He's benefitted the most from the franchise's decision to go all-in on small ball, as it has opened the floor for him to do what he does best — attack the basket with reckless abandon.

In theory, Westbrook couldn't be in a better situation to snap his cold streak in the playoffs. But will he? That's the $123.0 million gamble the Rockets took when they traded Chris Paul and picks to Oklahoma City for him in the offseason.

Ben Simmons, Philadelphia 76ers

We all know what happened in the Eastern Conference Semifinals last season.

While Simmons defended Kawhi Leonard about as well as anyone could've expected, he took a backseat to Joel Embiid, Jimmy Butler and Tobias Harris on offence, culminating in him sporting a usage rate of 14.9 percent in the second round, down from 19.4 percent in the first round and 22.1 percent in the regular season.

It was most noticeable in the clutch, as Simmons was relegated to hanging out in the dunker spot when it mattered most.

The 76ers still almost beat the Raptors despite Simmons fading into the background, but they can't afford for him to do it again because they no longer have the luxury of turning to a five-time All-Star in Butler when the offence grinds to a halt. Plus, Simmons just signed a five-year, $170 million extension in the offseason. Now that the 76ers have committed superstar-level money to him, they need him to take on more responsibility at the end of games.

Simmons won't be expected to be the only one one making plays with the game on the line — Embiid is still Philadelphia's best scorer and Harris is more than capable of creating offence for himself, as is Al Horford — but as Philadelphia's best creator in the backcourt, they will need him to be far more aggressive than he was last postseason to take down the likes of the Raptors, Heat, Bucks and Celtics in the playoffs.

A worrying sign? Simmons' usage rate in the clutch is actually lower this regular season than it was last regular season. If that trend continues in the playoffs, it could spell trouble for the 76ers.

Giannis Antetokounmpo, Milwaukee Bucks

I'm not going to lie, including Antetokounmpo on this list feels a little icky. He's already won one MVP award and he'll likely win his second at the season's end. Not only that, he's got a good chance of joining Michael Jordan and Hakeem Olajuwon this season as the only players in NBA history to be named MVP and the DPOY in the same season.

At the age of 25, Antetokounmpo has already proven to be one of the three best players in the league.

And yet, as much as I hate the "rings over everything" culture, there's no denying that Antetokounmpo has some unfinished business in the playoffs after what happened last season. Up 2-0 against the Raptors in the Eastern Conference Finals, the Bucks were in good position to advance to the NBA Finals for the first time since 1973-74. They proceeded to lose four straight games, with Kawhi Leonard getting the better of Antetokounmpo in each of them.

Antetokounmpo still put up big all-around numbers in the games Milwaukee lost, but his efficiency fell off of a cliff. In Game 3, which the Raptors won in double overtime, he scored 12 points on 5-for-16 shooting from the field and turned the ball over eight times. In Game 6, Antetokounmpo scored 21 points on 7-for-18 shooting from the field and turned the ball over four more times. He also struggled from the free throw line, going 17-for-36 from the charity stripe from Game 3 onwards.

Again, Antetokounmpo is already one of the best players in the league. In that regard, he has nothing to prove. But if he wants to widely be considered the best, leading the Bucks to a championship following a historic regular season would almost certainly do the trick.

Quick-hitters

Nikola Jokic, Denver Nuggets — Jokic has already proven that he can take his game to another level in the playoffs, so this is more about him doing it again with a bigger spotlight on him and against better competition.

Donovan Mitchell, Utah Jazz — Mitchell was spectacular in his first postseason run. His second? Not so much. This would be an opportunity to bounce back and prove that he's capable of being the best player on a contender.

Jayson Tatum, Boston Celtics — For the exact same reasons as Mitchell.

Anthony Davis, Los Angeles Lakers — We saw how much Davis means to the Lakers in their win over the LA Clippers before the season was suspended. The Lakers might not need him to play out of his mind to make the Western Conference Finals, but with potential matchups against the Clippers and Bucks, his time will come.

Paul George, LA Clippers — The Clippers gave up a lot to acquire George in the offseason, hoping he can be the Pippen to Kawhi Leonard's Jordan. He's been in and out of the lineup all season with injuries, but this break should help him return to full strength for what is expected to be a deep playoff run for the Clippers.

The views on this page do not necessarily reflect the views of the NBA or its clubs.