Matthaus insists Bayern can afford to sign both players.
He told Sky Deutschland: "Bayern could economically handle both transfers and buy Sane and Havertz at the same time.
“Before a big change, though, every top player asks himself the question: Where can I be almost sure to play if I perform? The Leverkusen player [Havertz], who is sure to be hunted by the vast majority of clubs, should in my eyes have the character and quality to assert himself at Real, Barcelona, Juventus or the top English clubs.
“A change may be more apparent at a club like Real. [Toni] Kroos and [Luka] Modric will no longer establish an era there.
“Havertz has made a very good impression on me and that, paired with insane talent, means he has what it takes to show his class abroad. But of course Bayern will also be a factor.
"It could also be an option to agree on the season after next, with Bayern allowing him to stay in Leverkusen for another year – especially if they qualify for the Champions League.
"Then Thomas Muller will be a year-and-a-half older and the prospects for Kai are even better than they are already. He will certainly cost at least 80 million, and only because of the current crisis. Otherwise we would be talking about a three-figure amount.
“Bayern must and will strengthen with top players. I assume that [Corentin] Tolisso may have the desire to change clubs in order to get more appearances, because he currently cannot get past [Joshua] Kimmich, [Leon] Goretzka, Thiago and [Thomas] Muller. [Javi] Martinez doesn't matter anymore either, and [Philippe] Coutinho won't play at Bayern next season. That means transfer income and salary savings.
“That's why I think FCB could buy Sane and Havertz. Whether they do this or wait for the situation with the coronavirus to be over is open to debate."