76ers' Tobias Harris, Al Horford out vs. Suns on Tuesday

The Philadelphia 76ers will be without four of their five regular starters on Tuesday when they take on the Phoenix Suns. The latest additions to the team's injury report, Tobias Harris and Al Horford have both been ruled out on Tuesday afternoon.

Harris, who has been relatively healthy all season long, will miss just his second game this year as he's dealing with soreness in his right ankle. Meanwhile, Al Horford is out with soreness in his left knee, which was a reoccurring issue for the veteran big man throughout the year.

In addition to those two, the Sixers will also be without the team's two All-Stars in Joel Embiid and Ben Simmons. As we know, Simmons injured his knee during last Wednesday's game against the Washington Wizards. After getting an MRI completed, Simmons was diagnosed with a subluxation in his left kneecap.

Therefore, Simmons and the Sixers decided that surgery would be best. On Sunday, Simmons departed from the bubble in Orlando and flew back to Philly to undergo surgery on Tuesday morning.

As for Embiid, his injury seems less severe. During Sunday night's game against the Portland Trail Blazers, Embiid landed awkwardly on his ankle just six minutes into the game. After leaving the court and heading to the locker room to get his ankle checked out, the Sixers ruled Embiid out for the remainder of the matchup. 

The Sixers take on the Suns at 6:30 PM EST. 

Justin Grasso covers the Philadelphia 76ers for Sports Illustrated. You can follow him on Twitter: @JGrasso_