Kenny, 37, has joined the Millers on a contract until the end of the season and will join Lee Camp and Alex Cairns in the goalkeeper's union at New York Stadium.
Warnock, whose brief is to guide the Millers to Championship safety, has previously brought Kenny to Bury, Sheffield United, QPR and Leeds and knows he can rely on the veteran.
"I felt, with every game a cup final, we needed someone like
Paddy in case Lee got injured.
"If anything happened to Lee, he would go
straight in without me worrying one little bit."
Kenny has been without a club since leaving Bury before Christmas and is relishing being back on the training ground.
"I'm delighted and
looking forward to it. It’s great to be back out on the training pitch and it’s
good to be able to help out," he said.
“It’s all I've known for the
last 17 or 18 years and I’ve felt like a big kid being back out on the training
pitch for the past week or so.
“I've just been gradually
building my fitness up. I've been doing a lot of running and gym work but when
you’re a goalkeeper the training is totally different. Getting up and down on
the floor is a lot different so I've been working with Andy Dibble and the lads
on that."
The goalkeeper becomes the third signing of the week at the Millers following the arrivals of fellow free agents Jerome Thomas and Lloyd Doyley.
