Grant was replaced as the club’s number one during the summer transfer window, when the Rams signed Scott Carson from Wigan Athletic.
However, rather than sulk, the 32-year-old stopper has worked even harder to win his place back – and his efforts have been rewarded in recent weeks.
Grant has started in Derby’s last four Championship matches, following an injury to Carson, and Clement has been impressed by what he has seen.
“It’s disappointing Scott that he has had to miss a few games because he’s made big saves at important moments for us; he has been consistent,” Clement said.
“But we’ve got Lee Grant and he is a very capable goalkeeper; as we’ve seen already.
“He has been extremely professional in his approach and he has been pushing Scott every day and preparing for his opportunity.
“Lee was disappointed not to play at the start of the season, but he has remained patient, gone about his work professionally and now he has his chance.
“I am in a privileged position really and Lee has shown the perfect mentality."
Grant’s performances for Derby towards the back end of last season were slightly erratic, and Clement clearly felt that upgrading his goalkeeper was a priority after being appointed at the iPro Stadium.
Carson has been very reliable in the Rams' net so far, but Grant has also proven his worth in recent fixtures.
The former Sheffield Wednesday stopper has kept three clean-sheets in his last four outings, and helped Derby keep up their hugely impressive defensive record.
Clement’s side have conceded just 13 goals in their first 22 matches, and they currently occupy one of the automatic promotion spots.