Vuskovic, 19, joined Hamburg on a season-long loan from Tottenham Hotspur in the summer of 2025 and has been one of the most influential defenders in the Bundesliga this season, making 27 appearances and contributing six goal involvements from the backline.
His absence across three consecutive defeats underlined how central the Croatian has become to Polzin's setup, with Hamburg conceding nine goals in those three games.
Under the terms of his loan agreement, Hamburg must obtain Tottenham's clearance before returning Vuskovic to match action following injury.
Polzin told Bild that communication with Spurs has been continuous throughout and that all parties appear aligned.
"Luka has been able to do almost everything with the team. He has definitely taken steps forward and is pain-free. We don't want to take any risky decisions. Luka has the option of returning to the matchday squad. We are trying to find a smart solution that helps him and helps us."
On relations with Tottenham, he was relaxed.
"It is our duty and our understanding to maintain close communication with the club and the player. Since he is back in training, you can assume that everyone is thinking and moving in the same direction."
Hamburg need results with four games remaining as they battle to put daylight between themselves and the relegation zone. A fit and available Vuskovic would represent a significant boost.
Those close to the situation rate his chances of remaining at Hamburg beyond this season as minimal. He is expected to return to Tottenham in the summer, where he will look to push for a senior role at the north London club.
Vuskovic signed for Spurs from Hajduk Split and is regarded as one of the most promising young central defenders in European football.