Qualification hopes of both countries appear forlorn ahead of their Group A clash in Glasgow.
The Scots are bottom of the table with two points from four games, one point behind Chris Coleman's men who won 2-1 when the two countries met at Cardiff in October.
Adam, however, promised the Tartan Army that they will see a Scotland team, in Gordon Strachan's first competitive game as boss, desperate to rescue their fading qualification hopes before the second of the double-header away to Serbia next week.
"We have to go for it, we are not in a good position and if we want to do something then we better start on Friday night," the Stoke midfielder said.
"We are a better team (than points total suggest) but we are the only ones who can fix it.
"We will need to attack and we will do.
"It is a challenge. Everyone in Scotland thinks we can win, the players think we can win but it is going to be a tough match."
Most of the build-up to the game has centred on Gareth Bale who scored both Welsh goals in the win over the Scots last year.
Adam acknowledged Bale's quality and form but insists the Spurs forward is not the only threat to Scotland.
"They have other players, they are not just a one-man team," said the former Rangers, Blackpool and Liverpool player.
"Real Madrid and Barcelona are not one-man teams.
"People keep saying it's about Gareth Bale and he is up there, one of the best in the world at the moment.
"He is a top player and we will probably have a plan to stop him but they have other players who are top players who play in the Premier League.
"It doesn't matter if we stop him or he has an off-night, it doesn't mean it will be an easier game for us."