Cahill left Melbourne City at the end of 2017 in search of regular game-time.

The Socceroo has rejoined his former club Millwall in the English Championship.

Cahill feels he is now in a "more professional environment" than at City, and stated he was "going through the motions" at the A-League side.

"I knew I needed to go straight away," the striker said.

"When you watch a Championship team train, the intensity is so high especially at Millwall. When you train in Australia, yeah, it's hard but it was comfortable and I needed more from it.

"Any Australian player who is playing A-League would jump at the chance of playing in the Championship.

"The A-League is not the Championship, that's not being disrespectful, it's just being honest. You're going through the motions. That's the mentality I have.

"The opportunity to be here was very hard to turn down. Some people might think 'what's he doing?' but I've never taken the easy road."