"They're seven points clear of seventh-placed Blackpool with three games left, it would be a tall order to drop out after that," Ratcliffe told BBC Sport.
"I've been very impressed with the way they've scrapped away and got results, it reminds me of the Cardiff of old."
He says those battling qualities will see them avoid last-year's collapse.
The Bluebirds took just one point from the last 12 on offer last season to unbelievably miss out on the play-offs by a single goal.
Three points from the nine remaining to them this season would guarantee a knock-out place.
"They look solid and like they won't concede," Ratcliffe told BBC Radio Wales.
"You always know that they can score goals, but there's a better chance if the defence perform like they did against Reading - they will get into a position where they will be more comfortable than last year."
Manager Dave Jones says he will be stressing the need to avoid complacency ahead of Saturday's game at QPR, the 24 April visit of Sheffield Wednesday and the 2 May trip to Derby.
"It's still tense, quite tight - we are taking nothing for granted," Jones told BBC Sport Wales
"One more win should see us there but it's getting that. If it takes three draws that's what it's going to take.
"If we can get to the end of the season without losing that will see us in good stead [for the play-offs]."
Midfielder Joe Ledley says he is in confident mood for the run-in and dismissed fears about his fitness after he came off in the second half against the Royals.
"I just stiffened up in the groin and hamstring, I'm glad it's nothing more," Ledley told BBC Sport Wales.
"We knew it was going to happen after my not playing for more than two months, hopefully I'll be fit for Saturday.
"It's great to be back playing good football, we're strong as a team and hard to break down.
"We'll take the point against Reading, especially with Blackpool losing.
"We'll dig in for the last three games and get as many points as we can.
"These are the most important games. Even if we don't play well but get the points, that's good for us.
"We feel strong for the finishing stages. It was a blow losing Gavin Rae, but otherwise we've a full squad and are looking good.
"The way we've been playing we deserve to be in the play-offs."
Source: BBC Sport
Source: BBC Sport