The Scotland international was a 74th-minute substitute during Celtic's shock 1-0 defeat at Kilmarnock, coming on at left-back for his first SPL appearance since October.
Brown is now in line to feature in Celtic's Active Nation Scottish Cup fifth-round clash against Dunfermline at East End Park on Sunday.
The 24-year-old is eager for matches after undergoing a lengthy rehabilitation from his second ankle operation of 2009.
Lennon told the club's official website: "Scott was excellent for an hour. He's just desperate to get back into the first team now and hopefully he'll figure at the weekend at some point.
"He's working his way back to full fitness and is a good indicator for where these other players have to be.
"He's the current Scottish player of the year, he's a full international and he led the way on the pitch.
"It's good to see senior players bringing these kids on. They will learn from playing beside guys like Scott and I have to give him credit for the attitude he showed out there. His appetite was fantastic."
Lennon was even happier to see 23-year-old Charlie Grant make his comeback following his latest injury.
The midfielder was a key member of the Scotland team that got to the final of the UEFA Under-19 championship in 2006 but has endured a succession of injuries over the last three years.
Lennon said: "Seeing Charlie out there was the highlight of the night for me. That kid has had horrendous luck with injuries over the last few seasons.
"He got 20 minutes and looked like he'd never been away. I was delighted to see him play.
"He got stuck right in as he likes to and reminded me a wee bit of myself!
"We will introduce Charlie back in gradually but I was happy for him."