The Oklahoma City Thunder will be without center Isaiah Hartenstein for 10-14 days. It’s a preview of what salary cap constraints might force their roster into next season.

Hartenstein suffered a calf strain that kept him out of Friday’s win over the Phoenix Suns, which ran the Thunder’s league-leading record to 19-1. On Saturday, the team announced that the injury was a strained soleus, a muscle in the lower calf, which will keep the big man sidelined for at least five games, including a rematch with the Suns in the NBA Cup quarterfinals.

Isaiah Hartenstein could be a cap casualty next season

Hartenstein was a key part of the Thunder’s title team last season after signing a three-year, $87M contract in free agency, where next year’s $28.5M salary is a team option. That might be too expensive for the Thunder, who will see the salaries of Jalen Williams and Chet Holmgren skyrocket to $41.5M each in the first year of their rookie extensions. MVP Shai Gilgeous-Alexander will actually make slightly less next season, at $40.8M, before his salary jumps to $61M in 2027-28.

With Alex Caruso set to make $19.6M, that means the Thunder have over $143M committed to four players. Add in Hartenstein’s team option and Lu Dort’s $18.2M team option, and they’re at $190M for six players, $24M above the salary cap. With their current contracts, they’d be at $246.6M, which is more than $23M over the projected second apron line.

That’s why Hartenstein is the most obvious player to depart. He’ll have the team’s fourth-highest salary, but it’s not guaranteed. OKC could turn down the option or trade Hartenstein to someone interested in one high-priced year of the center.

Isaiah Hartenstein doesn’t have much depth behind him

The Thunder have one of the NBA’s deepest rosters, well-equipped to handle any player’s absence. They went 18-1 while Williams, an All-NBA forward last year, recovered from offseason surgery. Holmgren, Dort and Caruso have all missed time, though Hartenstein had played all of the team first 19 games, averaging 12.2 points and 10.7 rebounds while shooting 67.1%.