The Oklahoma City Thunder are off to a 19-1 start, by far the best start in franchise history and the league’s top record. The OKC Thunder are also lapping the field in net rating and defensive rating, both historic marks while topping the NBA. However, they have done it through no shortage of adversity.

The OKC Thunder have missed more games due to injury than almost any other team in the NBA and have already played 20 contests including three back to back stints of their 13 all year. Oklahoma City saw two swingmen return this week, as veteran Kenrich Williams made his season debut on Wednesday and All-NBA forward Jalen Williams debut on Friday against the Suns.

Now, the Oklahoma City Thunder got even more bad injury news. After Isaiah Hartenstein missed his first game of the season on Friday due to what was labeled as ankle soreness. The Bricktown Ballers announced on Saturday night that the seven-footer would be sidelined for at least 10-to-14 days with a right soleus strain. in that time frame he will be re-evaluated with future clarification on his return to play.

Hartenstein will at the very least be sidelined for five games in that span, including the team’s NBA Cup knockout round matchup against the Phoenix Suns, the same team he was absent against on Friday.

The Oklahoma City Thunder are going to miss the seven-footer’s presence on the inside, as made clear by his lone game missed thus far being a contest the Thunder were crushed on the glass, losing the rebounding battle 51-37 and the points in the paint category by four.

Hartenstein’s screen-setting ability to create space for his drive-heavy guards and high-post playmaking to capitalize on a roster full of cutters for easy points will be hard to replicate for this squad despite its depth and really hamper the team’s offense for however long he is sidelined.

It is important to note this 10-to-14 day window is just a re-evaluation date and not a guaranteed return date by any means. This is a lower right calf strain in the most simple of terms and every NBA team should be careful with anything related to this area of the body with the devastating run of achilles injuries this league has suffered through over the course of the last calendar yet.

Last season, Hartenstein missed 12 days of the NBA season with this same issue, which should give confidence that there is a plan in place to manage things for the Thunder big man.

Stay tuned to Thunder on SI for more on this story and complete coverage of the Oklahoma City Thunder’s season.