The 19-year-old's representative, Viktor Kolar, claims City were among several top English clubs chasing the youngster, while high-profile sides in Germany were also interested.
However, Kolar says the Czech Republic U19 international chose Sparta because he wanted to be playing regularly.
The agent told isport.blesk.cz: "Top clubs from England and Germany wanted him. Among them was Manchester City.
"Tomas' age means he needs to be at a club where he will be playing in a top league. That's why we opted for Sparta."
Prikyl added: "I have always made small and gradual steps and I believe I have chosen the right path by joining Sparta."
The teenager, who joined Sparta from native club Sigma Olomouc for £500,000, caught the eye of Europe's top clubs on duty for Czech Republic at last summer's U19 European Championship.
Sigma rate Prikyl as highly as young Chelsea defender Tomas Kalas, currently on loan at Vitesse, according to Sparta board member Jakub Otava.
He revealed negotiations with the club were lengthy, saying: "It's because Sigma consider Tomas, along with Tomas Kalas, their greatest talent of recent times."