Members of the 45-strong squad have just six matches to stake their claim for a place in the first meeting with the All Blacks in Christchurch on June 24.
There are a clutch of rugby superstars in the touring party but Woodward has vowed they will only enter his Test-match thinking if they prove themselves in the preceding weeks.
"I've got an idea of who I will pick to play the All Blacks, but it's no clearer than anyone else's who has been following the tour up to this point," he said.
"People tend to come through very strongly on Lions tours. Guys you might not initially think should be in the Test side when the squad is announced start to impress and force their way into the reckoning.
"That's what touring is about and I don't see this trip to New Zealand being any different. I'll be looking very closely at what happens in every game. We'll be picking on form for that first Test match, not on reputation."
Three players will link up with the squad at a later date. Wales fly-half Stephen Jones leaves for New Zealand on Sunday after honouring his commitments with French club Clermont Auvergne.
Jones' Welsh team-mate Gareth Thomas has so far been unable to agree a departure date with Toulouse, the European Cup winners who have yet to complete their domestic season, while Jason Robinson is to spend some time with his pregnant wife Amanda.
Woodward said: "Stephen Jones is flying on Sunday and we're still looking for final clarification on Gareth Thomas. We're speaking to his club but we haven't got a definite date for him yet.
"We're trying to get him out to New Zealand as soon as possible. Toulouse are his main employers so we don't want to jeopardise Gareth's future. We want him to come out when he feels he can.
"I've been kept informed of the situation by Jason over the last few weeks. Yesterday we decided to send him home for a few days. We've pencilled his arrival in for early June.
"Obviously there is a slight question mark over him but we don't what him to join us until he feels he can do that."