The England international will be back Wednesday, this time wearing a Sunderland shirt in an exhibition game at his old MLS stomping ground.
"I've got lots of good memories from my time there," he told the Sunderland website. "I met some great people and they're a really good club. I'm really looking forward to going back, it’s a nice place to go and I enjoyed living there.
"They've got a fantastic set of fans and I'm looking forward to seeing some familiar faces when I go back. I'm still friends with the lads I played with there."
Defoe scored 11 goals in 19 matches in an injury-interrupted 2014 MLS season. Still, Toronto never lost a league game in which he scored.
Toronto sold Defoe to Sunderland in January with U.S. international forward Jozy Altidore going the other way.
Defoe insisted he was committed to Toronto and never asked to leave. But it was clear he wanted to go home.
It didn't help that he returned to England during the season for injury rehab, with Maple Leaf Sports & Entertainment president Tim Leiweke telling a Ryerson crowd that he did not expect him back.
The former West Ham, Portsmouth and Tottenham forward confirmed he missed England.
"I know a few people didn't understand why I left, but for me I just missed the Premier League," Defoe was quoted by the Sunderland website.
"I'd played in the Premier League my entire career and I just love my football and I wanted to come back. When you step away from the Premier League you really miss it, that’s why I wanted to come back."
The 32-year-old Defoe, whose TFC salary last season was listed at US$6.18 million by the MLS Players Union, scored four goals in 17 games with the Black Cats.
The 25-year-old Altidore, who is making $4.5 million this year, has six goals in 13 appearances for Toronto.
Italian dynamo Sebastian Giovinco has already surpassed 2014 Defoe's scoring total. The 28-year-old Giovinco has 12 goals in 18 league games for Toronto.
The Toronto game marks an end to Sunderland's North American trip.
The Premier League team held a weeklong training camp in San Francisco before losing 3-1 to Mexico's CF Pachuca and 1-0 to the Sacramento Republic, both in Sacramento.
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