"And with this boy he's taken a massive gamble coming to us. There are things that he's done which you don't normally come across in a player.
"He wants to prove his worth at this football club and show everybody that he's still capable of playing here rather than going back to Spartak.
"We can give him that stage. He's got to deliver the goods and hopefully he will do."
Wales international midfielder Ledley has been linked with £6m moves to Premier League sides Wigan Athletic, West Ham United and Stoke City.
And Bluebirds fans feared that Owusu-Abeyie has been signed to fill the potential void of their captain.
But Ridsdale maintained: "We intend on giving Dave the best chance of getting promoted and we see no exits from the current squad."
Cardiff chief Ridsdale revealed that he is in talks to sign a top-level striker before Monday evening's January transfer window deadline.
"We're still after a striker before the deadline on Monday at 1700 GMT," said Ridsdale.
"We have got an option to purchase Quincy in the summer and if we exercise that option he has to come to us, that is a clause we have put in the deal.
"We got him at a price we thought was right and proper.
"He's a good player with great pedigree who can play up front and on the wing."
Owusu-Abeyie was a member of the renowned Ajax youth academy in his home-town of Amsterdam for nine years and was picked up by Arsenal after he was released from the Dutch giants.
He was highly-rated by Arsenal but failed to break into the first-team on a regular basis and joined Spartak Moscow in January 2006.
Owusu-Abeyie played on loan at Spanish club Celta Vigo before impressing in a temporary spell at Birmingham City and scored against Cardiff while he was on loan at St Andrew's earlier this season.
But he left Birmingham earlier this month and Cardiff confirmed the former Dutch under-21 international as their second January transfer window signing on Saturday after sealing a permanent deal for Chris Burke from Rangers.
"We are pleased to have completed the deal," Ridsdale told BBC Sport.
A Cardiff statement added: "Quincy will link up with the squad on Monday in readiness to prepare for our Championship encounter with Charlton next Saturday."
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