Pujara dropped Cook at the slips off Zaheer Khan when he was on 17 before the England skipper went on to make a record-breaking century in the second day of the ongoing third cricket Test here.
"Pujara has been practising a lot in the slips. He's been one of our better slip fielders over the last month or so. I know he dropped a catch today which was pretty crucial but that happens in cricket. He (Pujara) got both hands to it but he just dropped it," the 44-year-old Zimbabwean said in the post-day's press conference.
Cook remained unbeaten on a brilliant 136 to lay the platform for England's 216 for one in reply to India's 316 all out in the first innings.
With India feeling the vacuum in their slip cordon after specialists Dravid and Laxman's retirement, Penny said the team's think tank was working towards developing fielders who can field at any position.
"It's different from those old days when you go in and never come out again and then you become a slip specialist. It's changing a little bit in general," he said.
"Certainly Pujara is a good catcher and R Ashwin can catch as well. Suresh Raina, not in the Test side, has got good hands. Virat's (Kohli) good as well. I reckon those four will take the spots," Penny added.
On a day Indian fielders struggled especially in the slip cordon, Virender Sehwag was absent from his usual position in the slips with Pujara, sporting shin pads, and Ashwin doing the job. MORE