The Frenchman has been linked with moves to
and Barcelona in recent months but neither of those clubs have made an approach amid the coronavirus pandemic.
Speaking to Kicker, Krosche said that Upamecano needs to make a decision over his future with his existing deal at Leipzig due to expire at the end of next season.
However, he added that the Frenchman should take his time and is hopeful that the centre-back will renew his contract with the club rather than pursuing a fresh challenge.
"This is a far-reaching decision for a player. He should take his time with that. He has to be clear about exactly what he is going to do, how he sees his future. Maybe that has changed a bit as a result of the new situation," he told.
Upamecano has a release clause worth £55m in his current deal and it appears unlikely that either
or Barcelona will meet the valuation without offloading some of the out-of-favour players.