The Danish midfielder has been one of the shining lights in a difficult Championship season, and sparked the last home league win over Blackburn with a thrusting second half cameo.
But head coach confirmed ahead of Birmingham’s visit Schwartau suffered a hamstring injury in the FA Cup win over West Brom.
The Belgian is already without attacking duo Papa Amadou Diallo (quad) and Matej Jurasek (foot) in wide areas.
“It’s not a big, big one, but he will be out for a few weeks. We didn’t expect it with him, because he’s been really robust and he’s been playing a lot of minutes. But this can happen,” said Clement. “This is part of football. He is also still only 19 and people forget that sometimes.
“He had his biggest sprints that he had until now in the club, the biggest speed, and he felt his hamstring afterwards. It’s not a big, big thing, but he felt his hamstring so probably his body didn’t follow the speed that he was reaching.
“So the amount of work that he’s done already this season has been massive, and with really good progression also for me in these three months. Of course we’re going to miss him the next few weeks. But again, it’s like in the other situation, an opportunity for others to show themselves.”
Amankwah Forson is available for the Blues’ Carrow Road visit after being eased back into the fold after his latest hamstring injury.
Clement spoke last week about the need to build that ‘robustness’ across his entire squad moving forward after an injury-blighted spell in the past couple of seasons.
“It’s a big focus,” he said. “They all have the ambition to go to the Premier League. We talked about that. We all have this ambition, and you need to be robust to play at that stage every three days, and you need that in the Championship. A little bit lower level, but it’s not a massive difference. So we need to make them more robust to cope with that.
“I had a talk (on Friday) with Forson about that, also that we need to break this cycle that he’s been having, not only here, but also in his club before.
“Vlad (Kovacevic) is back in training. Jakov (Medic) is back in training. Forson had his first training week, also without restrictions. So those are also positives.”
Clement also updated on Manchester United loanee, Harry Amass, who has returned to his parent club to continue his rehab from a hamstring injury that limited him to one substitute appearance. But the Belgian insisted City are not prepared to call time on the half-season loan.
“No, no, for sure, not. I’m still in contact with Harry, and we’re in communication about this rehab. So we’re doing this rehab together with Man U,” he said, who deflected a question whether he will explore the potential to bring Amass back on loan next season.
“That’s far away, so let’s focus on the here and now and also this season. I hope still in a really good scenario that Harry can play for us at the end of this season. I hope also to keep this season as long as possible. So let’s see.”