The 26-year-old will be sentenced next month after he pleaded guilty to the double assault at Airdrie Sheriff Court on Monday.
Lennon confirmed Saints will discipline the player but the Buddies boss also promised to put an arm around the former Celtic youth's shoulder and help him learn the error of his ways.
He said: "You're not always just a coach to these guys, sometimes you are a father too. But it's about how you come through the tough times and Paul truly regrets every mistake he has made.
"It's getting dealt with [by the courts] and he goes back up in January. What will happen will happen. But until then we will do everything we can to help. It's up to us to help guide him back onto the right track."
McGowan admitted kicking Police Constable Edward Gilmartin on the body and repeatedly kicking Sergeant Tony Fitzpatrick on the body during the incident in his home town of Airdrie and then later at Coatbridge police office on August 11.
Sheriff Petra Collins deferred sentence on McGowan until January 8 for reports, while his bail was continued.
But Lennon defended the player's character as he vowed to continue naming the ex-Morton and Hamilton Accies forward in his line-up.
"Paul is no problem for us," he said. "Everyone makes mistakes throughout life and it's about cashing in on the lessons they teach you.
"He's not a bad lad. In fact he's a lovable wee character. He just loves playing football. In fact he would kick a ball about 24 hours a day. Maybe that's how we calm him down - just put a ball at his feet and let him run about all day.
"The club will take action against him but it will be dealt with internally.
"But it's not a tough situation for me. Don't get me wrong, you never like to see trouble coming to your door and I want my players to go out there fully focused on their job. However, all that has happened has not really hampered Paul."
Meanwhile, Lennon says he does not "envision any problems" with attempts to secure on-loan Newcastle midfielder Conor Newton for the rest of the season.
The 22-year-old's current stint is due to finish on January 1 but he could see out the season in Paisley alongside another Geordies youth.
Adam Campbell is set to become the third Magpies player in 18 months to head north as part of an affiliation pact between the clubs and Lennon believes a deal will benefit the England Under-19s striker.
"If the right people come along we are certainly in a position to do a little bit of business," said Lennon, who failed to land Campbell back in August.
"Adam could be one of them. We have had good dialogue with Newcastle, the player and his representative. It's a partnership with Newcastle that has worked well for us.
"There is a good understanding between both clubs and we have already the proof in the pudding with Paul Dummett going back there to their first-team and Conor Newton has kicked on since last season.
"These players really do go back better players. That's not just down to us but it's the experience of getting weekly football and I see no reason why young Campbell wouldn't progress just the same."