Providing the Welsh can win on aggregate they will move into next season U21 Championships. Failure to win will see a year without any competetive football.
The Wales team for this evenings game is
Wales U21: Lewis Price (Ipswich Town), Simon Spender (Wrexham), Rhoys Wiggins (Crystal Palace), Andrew Crofts (capt, Gillingham), Craig Morgan (MK Dons), Mike Williams (Wrexham), Shaun MacDonald (Swansea City), David Edwards (Shrewsbury Town), Craig Davies (Hellas Verona), Ramon Calliste (Liverpool), Arron Davies (Yeovil Town).
Subs: Chris Gunter (Cardiff City), Gareth Bale (Southampton), Lloyd James (Southampton), Rob Davies (WBA), Dale Williams (Yeovil Town), Curtis McDonald (Cardiff City), Sam Pearce (Bristol City).
"Estonia will come at us because they are 2-0 down," said Wales U21 manager Brian Flynn.
"It is not going to be easy and we know just how important it is to win this qualifier to get into the Uefa Championships next season."
"They will have looked at us now and worked out how we play, so it was important we were able to experiment in the friendly to give ourselves some different options," Flynn added.
"They will not have given this tie up, we know we have to stand up to them.
"But we have been together a few days now, it's good for us and it helps us gel as a side."
5 players, Rhoys Wiggins, Arron Davies, Craig Davies, Gareth Bale and Andrew Crofts will all join back up with the senior squad as they prepare to face Trinidad & Tobago in Graz on Saturday.