Gerrard's team has also been bolstered by the arrival of AS Roma forward Umar Sadiq and midfielders Ovie Ejaira and Lassana Coulibaly on season-long loan deals.
"There's no number on it," Gerrard told reporters. "We'll be there when we're there.
"When I see that the team and the squad is strong enough to compete against the best sides domestically and also against teams we are going to come up against in the Europa, that's when we will be ready.
"Good players are on the same wavelength and good players gel pretty quick and that's what we've tried to into the transfer market for - for good players, for talents. We're trying to get the right balance and the right blend."
Gerrard, a former Liverpool midfielder, made his managerial debut against English fourth-tier club Bury F.C. in a friendly last week.
The 38-year-old will lead Rangers in his first competitive match in charge when the Scottish side host Macedonia's FK Shkupi in the first leg of their Europa League preliminary qualifying round tie later on Thursday.
(Reporting by Aditi Prakash in Bengaluru)
