Unfortunately, for both the Club and Mauger, the passport never arrived and he's been forced to spend a lot of time on the bench or in the stands this season, as Zurich Premiership clubs can field just one overseas player at any time (Duncan McRae is Gloucester's other), while two are allowed in the Heineken Cup.
Mauger leaves Gloucester on Tuesday for a new contract in Japan with Ricoh Black Rams, the former club of new London Irish director of rugby Brian Smith.
Talking to the official club website about his season, the New Zealander's frustration was noticeable.
"Frustrating is about the best way to sum it up. I admit I took a gamble coming here without the passport, and that risk turned out not to be favourable.
"It's still a genuine mystery to me as to why the passport never turned up. I was always told it was on its way, which just added to the frustration."
Mauger, who only made sevens starts scoring three tries in all competitions this season, couldn't be on the pitch for Gloucester in the Premiership at the same time as Duncan McRae.
With the form of McRae, Fanolua and Paul on an upward curve in the opening two months of the season, Mauger was a frustrated bystander.
"I just couldn't put any consistent rugby together, and play week in week out. As a consequence I couldn't get any momentum together and play myself into form."
Before Mauger joined the West Country club he played a key role in the Crusaders' successful Super 12 set-up and toured with the New Zealand national side a few years back.
"I've got my own high standards, and when you're only playing here and there, it's not possible to meet them, or better them.
"Even though the season has been a disappointment I'm still glad I came as I've made some good friends, both players and supporters.
"In terms of development it's been good to see the way the game is played in the northern hemisphere, and I'm sure I've become a more well-rounded player."
It's been a tough year for Mauger and he was always keen to prove a point to the everyone, as to his ability.
"I don't think everyone understood. When you come to a new club you want to get straight out there and prove to everyone you're a good player and win their respect on the field. I had limited opportunities to do that.
"As a new signing, that's the first thing you want to do, it settles you down and makes you feel more comfortable."
The longest run of games the Kiwi midfielder managed was four starts in November and December against Wasps, Saracens, Sale and Cardiff.
"I'm still going to be 27 when the Japanese season comes to an end and we'll see where I go from there.
"But the one thing I do know is that I've missed the rugby. I love the game and I've played it all my life. I know I had more to offer, and I know I'm capable of more than I showed at Gloucester.
"The passport thing was out of my control, but if I'd been able to get a few more games together I could have done something.
"The fans here at Gloucester are as mad for the game as they are back in Canterbury, but they're closer to the pitch at Kingsholm. I've never encountered anything like it is here before.
"I'll miss the people and the place, but as a rugby player I've got to play the game, and the move to Japan will give me that, and also a new experience.
"But first and foremost is Saturday and the game against Saracens. I'm not involved with the squad but we've got players good enough to make it happen, and qualify for next season's Heineken Cup."
Everyone at Gloucester Rugby Club would like to wish Nathan Mauger all the best for the future.