The Lions face Argentina at the Millennium Stadium on Monday night as a precursor to the main event, which starts on June 4 against Bay of Plenty.
The aim against the Pumas is to lay foundations which can be built on in New Zealand and McGeechan was quick to play down the notion the Cardiff clash was merely a warm-up game, instead citing it as a chance for players to strike an early blow in the battle for a place in the starting XV against the All Blacks on June 25 at Jade Stadium, Christchurch.
"We see this as the first game of the tour," he said.
"There is no doubt we see this as the first game of the tour and so it is the first opportunity. It is also great someone like Michael Owen can captain the Lions in his own country.
"We have trained all week as one squad so the players have been doing everything together.
"Although there are two coaching teams, we have come together pretty quickly and the players are one squad," he added.