Lewandowski has stated his determination to leave the Allianz Arena in the coming weeks after growing frustrated with life in Bavaria.
Barcelona are locked in talks with the Polish international but Bayern are standing firm on their €60m valuation of the veteran striker, despite his contract expiring in 2023.
However, Lewandowski is not the only European hotshot looking to move on this summer, with Ronaldo restless at Manchester United.
The former Real Madrid attacker wants to play Champions League football next season, and he is pushing to leave Old Trafford, if a suitable offer comes in for him.
With both players looking to leave their respective clubs, Matthaus believes the solution is simple, if Barcelona can agree a fee for Lewandowski.
“If Bayern think Ronaldo is physically able to help for one or two years, they can invest the transfer fee generated by Lewandowski”, as per reports from Mundo Deportivo.
“I would really think about it, as Cristiano is still an exceptional goal scorer.
“Of course, he would not be a signing for the future.
“He is 37, but he would be a permanent starter.
“He is one of the best forwards of all time and would surely score about 30 goals.”
Ronaldo is currently the top scorer in European Cup/Champions League history, with 140 goals, with Lewandowski in joint third place, on 86, alongside Karim Benzema.