"Such a normalisation would give monetary policy more room to manoeuvre to react to any future economic slowdown," the Bundesbank president said in a Vienna speech.
The present economic upturn, which saw the 19-nation eurozone hit growth of 2.3 percent last year -- its fastest expansion in a decade -- "will not last forever," the economist warned.
ECB governors have already begun inching towards the exit from their support to the economy.
Since January, the Frankfurt institution has slashed its monthly purchases of government and corporate bonds by half, to 30 billion euros ($37 billion).
They see less need for the so-called "quantitative easing" scheme, designed to boost lending to firms and households with the aim of fuelling growth and powering inflation towards the ECB target of just below 2.0 percent.
Nevertheless, purchases are set to continue until at least September and likely longer if policymakers want to avoid a sudden stop.
Meanwhile, interest rates will not rise until "well after" the end of bond-buying, according to the central bank's regular policy statements.
The ECB's main refinancing rate is at zero, while its deposit rate is -0.4 percent -- meaning banks have to pay to park their cash with the central bank.
With higher rates, the ECB would have the option of lowering them again to stoke activity next time a crisis hits -- the usual way central bankers try to influence the economy.
But policymakers are for now leery of hobbling the eurozone recovery by raising rates just as growth is reaching full pitch.
German central banker Weidmann, seen as a strong candidate to succeed ECB President Mario Draghi after his term ends in October 2019, has long argued for an end to easy-money policy.