She went on to make five appearances in total and scored two goals.
"I will be forever grateful to the club, my teammates and Spurs supporters for taking such good care of me and my family," Morgan said in a statement.
"From the moment I arrived in London, I realised I was part of a first-class organisation, one that helped provide me the opportunity to immerse myself back into the game I love.
"Thank you to everyone who helped make this chapter in my soccer journey so special... COYS."
Sources told ESPN in September that there was a clause in her contract with Spurs which would have allowed her to stay at the club until the end of the 2020-21 WSL season.
However, Morgan said at a news conference in October that she was eager to help the National Women's Soccer League grow and didn't see herself staying in England for longer than a year.
"I think that after pregnancy I needed to get as many games in as possible leading to 2021 knowing that the Olympics will hopefully be on next year," she added.
"I wanted to make sure to put myself in the best position possible to get ready for that and I thought that competing in one of the best leagues in the world right now while it started back up after lockdown was the best option for me. Joining Spurs was important to me because it's such a good organisation."
Morgan's last game in a Tottenham shirt should have come at the weekend against Chelsea but it was cancelled due to a number of COVID-19 cases in Emma Hayes' squad.