The 22-year-old left-hander was hailed as a future successor to retired all-rounder Kapil Dev after his impressive debut as a teenager until his bowling form deserted him last year.
His confidence ebbed when he was sent home from South Africa in December and did not make the starting XI at this year's World Cup, where India made a first-round exit.
Pathan was omitted for the current England tour when he turned to the MRF Pace Foundation in Chennai to work under chief coach Lillee and former India bowler T A Sekhar.
"I've been working for nearly a month at the Pace Foundation and I am feeling pretty good," he said.
"Lillee worked on my technical flaws, in the use of my non-bowling arm, my run-up," he said. "I'm feeling positive now."
Pathan is hopeful he can prove his form on the India A tour of Zimbabwe and Kenya starting this month. He is also among the probables for the Twenty20 World Cup in September.
He made his debut in late 2003 and his ability to swing the ball as well as bat won him regular berths in both forms of the game. Pathan has 91 wickets in 25 Tests and 115 scalps from 73 one-dayers, averaging around 25 with the bat in both versions.
His finest hour came on the Pakistan tour in January 2006 when he claimed a hat-trick in the first over of the third Test in Karachi, although India lost to concede the series.
Pathan said his slide began soon after.
"I actually began developing these flaws nearly one-and-half years ago when I got the hat-trick," he said. "I knew there was something wrong, but didn't have much time to correct it."
He sought out former pace greats, Pakistan's Wasim Akram and West Indies's Andy Roberts, but to no avail.
Pathan is confident things would be different this time.
"I haven't played many games in the recent past," he said. "I need to do that to get back into the side."