Dublin's 2011 All-Ireland-winning captain Bryan Cullen says his county's highly fancied Under-21s are going to have to tighten up at the back to beat Kildare in tonight's Leinster final in Navan (7.30).

The Dubs, with eight of the current U21 squad involved with Jim Gavin's seniors, go into the Pairc Tailteann showdown with a weight of expectation on their backs against an impressive Lilywhites side.

But Cullen, an Eirgrid Under-21 Football Championship Ambassador, told Newstalk's Oisin Langan that Dessie Farrell's men have the firepower to prevail but that the concession of goals so far in the championship is a cause for concern.

"There's obviously huge expectancy on this Dublin team given the amount of senior players they do have," said the Swords man, himself an All-Ireland Under-21 winner in 2003.

"Concerns they would have ... they've leaked five goals over the last two games. They've had a bit of a tendency to have a slow start in games.

"[Kildare] have been scoring well so it's certainly the best forward line Dublin are going to have faced to date. So that's an area they'll really need to tighten up on.

"If they can keep things tight at the back, try and tie up Niall Kelly, keep it tight particularly early on ... I think they certainly have the talent up front to pull away."

Attached is the Dublin U21 Football team named to face @KildareGAA in the #LeinsterU21FC Final tomorrow #AllianzGaa - pic.twitter.com/uuuoQwgnFP

— DubMatchTracker™ (@DubMatchTracker) April 1, 2015