Neuer has been with Bayern Munich for the past eight seasons after joining from Schalke 04 for a fee of £13m in the summer of 2011.
The 33-year-old has been successful during his time in Bavaria, winning seven Bundesliga titles, four DFB Pokals and the UEFA Champions League in 2013.
Bayern Munich were pushed all the way by Borussia Dortmund en route to the Bundesliga title last season while they suffered elimination at the hands of Liverpool in the UEFA Champions League last 16 stage.
The exits of Mats Hummels, Franck Ribery, Arjen Robben and Rafinha have robbed Bayern Munich of some much needed experience and although they have brought in Lucas Hernandez and Benjamin Pavard, they are still short of the needed quality to compete with Europe’s biggest clubs.
Kroth reckons his client would like to win the UEFA Champions League once again, and the world cup winner could look to leave the club if they fail to bolster the side to challenge for continental laurels.
"He wants to win Euro 2020 and he wants to win the Champions League again. Manuel is success-oriented," Kroth said.
"My impression is that the gap to the top four English top teams is already serious and the Munich squad is currently not yet as competitive or set up to tackle Manuel's goals seriously. When he realises that Bayern are responding, then he will probably blossom again.
"He does not want to retire in 2021. Now he is in the phase in which he has to decide: how will things progress in the future?
"Signing a contract extension and ending his career at Bayern is of course the obvious option, but it's not the only one."
Neuer has two years remaining on his Bayern Munich contract.
