“One innings doesn’t make a cricket career,” Lehmann said.
The sobering message comes a day after Australia celebrated winning the Ashes.
Marsh, recalled for the third Test in Perth, made 181 against England in a triumph that delivered Australia an unassailable 3-0 lead in the five-match series.
“The challenge for him is to back that up again, to be perfectly honest,” Lehmann said.
“For him, he has got to back that up next game and do the right thing and continue to make runs.”
While thrilled with his batting, Lehmann admitted concern at Marsh’s bowling in Perth — match figures of 0-57.
Marsh also dropped a sitter of a catch at first slip in England’s first innings.
“I thought his bowling was a little bit disappointing, which he spoke about with me,” Lehmann said.
“He has got to get his bowling right, his fielding right and his batting. And if it all comes together, that’s fantastic.”
But Lehmann did admit feeling pride for the Marsh family.
Mitch’s brother Shaun made a ton in the second Test win in Adelaide, with the siblings’ feats delighting their father and former Australian opener and coach Geoff.
“It’s quite emotional when you see Swamp (Geoff) and Shaun,” Lehmann said.
“Swampy’s had an unbelievable two weeks for the Marsh family with Adelaide and now Perth.”
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