The Blues are thought to have approached the 20-year-old during the last transfer window as part of their world record £273million spend.
The defender remained at the Bundesliga club despite the interest but Kovacic acknowledged that he would love to see his Croatia teammate at Stamford Bridge.
"At the club, they asked me about Joško, I told them all the best," Kovacic said at Stadion Maksimir. "I don’t need to say anything about his football, they know what kind of player he is, and his character is excellent.
"I have seen in the national team how eager he is to play, he has a great career ahead of him, and I hope that one day we will play together in the club."
Chelsea face Dinamo Zagreb tomorrow where the duo started their careers before moving to Europe’s big five leagues.
The 28-year-old was wearing a warm smile in Zagreb as he prepares to face his boyhood club in a homecoming match on Tuesday night.
However, he has been overcoming a niggling knee injury which Tuchel has been trying to manage so he can avoid needing surgery to repair it.
Kovacic revealed that he believes he is overcoming the issue now and is positive that he will avoid a prolonged spell on the sidelines.
"I’m getting better, I had some problems with my knee after national team and pre-season," he added. "It was a tough pre-season for me but I’m recovered now and getting better day by day. I need to get my match fitness back but games and training are there for that.
"So I’m looking forward to getting better every day."