The top-seeded Boston Celtics will open the Eastern Conference semifinals on Tuesday without center Kristaps Porzingis, who vowed to recover from a calf injury “at a historic rate.”

Porzingis was diagnosed with a right soleus strain, which he sustained in the second quarter of Game 4 of Boston’s first-round series against the Miami Heat. He told reporters Saturday that his timetable is week-to-week.

The Celtics will face the winner of Sunday’s game between the Orlando Magic and Cleveland Cavaliers in the next round of the playoffs, which are set to begin Tuesday in Boston.

“It’s something; it’s not nothing,” Porzingis. 28, told reporters Saturday. “So it will take a little bit of time, for sure. But I’m doing everything I can to speed it up because I want to be back out there as soon as possible. But also understanding the worst thing would be probably to re-aggravate that, so being smart about it.”

With the length of the NBA playoffs — the conference finals begin May 19 at the earliest and the NBA finals are scheduled to open June 6 — it isn’t out of the question to think Porzingis could return at full strength to join the Celtics should they make a long run in the postseason.

Still, he is frustrated not to be on the court with his teammates.

“I’m not gonna lie, it’s tough,” he said. “First few moments were really tough. It gets you down for a second. But it is what it is. It’s part of the sport and these things happen and the best I can do now, is I have to do to get healthy as soon as possible and follow the plan and make sure I do everything and just get in that mindset because I can’t change what happened in the game. So just looking forward to making quick steps forward toward being back on the court.”

Porzingis is in his eighth NBA season and has career averages of 19.7 points and 7.9 rebounds with the New York Knicks (2015-18), Dallas Mavericks (2019-22), Washington Wizards (2022-23) and Celtics. He missed the 2018-19 season due to an ACL injury.

In his first season with the Celtics, Porzingis averaged 20.1 points, 7.2 rebounds and 29.6 minutes over 57 games (all starts). In his four playoff games, he averaged 12.3 points and 5.0 rebounds.

Porzingis has not been in the playoffs since 2021 with the Mavericks. He has appeared in just 14 career playoff games.