The striker's father has claimed that the Gunners were on the tail of the highly rated young forward this summer.
He netted 40 goals in 131 appearances for Sparta Prague since his professional debut, despite only being 19.
"There was Newcastle, they were somewhere else financially. Lyon, Sevilla, Dortmund, Bayern… however, we wanted to give the next step a little sense, so as not to jump to a mega club right away," Zbynek Hlozek told iSport.cz.
"When Leverkusen was almost done, we heard about a huge intervention from Arsenal. But the negotiation was already a long way down the line.
"Borussia Monchengladbach were the same, they spoke to Adam personally twice in the spring.
"They were excited about him but they didn't have the financial strength."