The Oklahoma City Thunder's stint without a center will end Wednesday night with the debut of 7-footer Isaiah Hartenstein.

Hartenstein is active for Wednesday's home game against the Portland Trail Blazers, the team said about 30 minutes before tipoff. He was sidelined for the first 15 games of the season because of a broken left (shooting) hand suffered in the preseason finale.

The Thunder signed Hartenstein to a three-year, $87 million contract in free agency this summer, planning to pair him with Chet Holmgren to allow Oklahoma City to always have an outstanding rim protector on the floor.

However, the Thunder haven't had a starter taller than 6-foot-6 since Holmgren suffered a right iliac wing fracture when he took a hard fall in the Nov. 10 loss to the Golden State Warriors. Holmgren, the Rookie of the Year runner-up last season, will miss at least eight to 10 weeks.

Reserve center Jaylin Williams has yet to play this season because of a hamstring strain originally suffered in training camp and recently aggravated.

The Thunder (11-4) have lost three of their past six games, a stretch that began on the night that Holmgren exited in the first half against the Warriors.

Hartenstein, 26, played a key role in the New York Knicks' 50-win campaign last season, averaging 7.8 points, 8.3 rebounds and 1.1 blocks in a part-time starting role.