When you look back at Sam Gagner`s pre-NHL career, you can see why he was so highly regarded ... but you can also see the big warning sign that signalled that all was not well with him.
Looking back, you can see his brilliant AAA career when he made the league his plaything for four years. Scoring well over 100 points each year, he was simply marvelous and was a superstar. When he moved on to the OPJHL, he slowed down substantially, but still managed a point a game there. The next season, as a 16 year old, he put up good, but not great numbers, in the USHL when he could not break the point a game barrier.
His only season in the OHL, as a 17 year old, he once again regained his fantastic scoring touch as he lit up the league for 118 points during the season.
The one big setback for him was the WJC20 tournament. Where he should have played a major role and scored at a good pace, he laid a big goose egg. Getting zero points in a major international tournament like the WJCs is a big warning sign. As an example, Patrick Kane (his London Knight teammate) was getting close-to or above double digit points in each of his three international junior tournaments that he played in ... a definite sign of good things to come. Paajarvi, for all of his great point totals over the years pre-NHL, scored only two points in six games at the WJC20s in 2008-2009 and now he struggles to stay in the NHL. Great NHL scorers will preform well in international tournaments. There are only a few exceptions to this.
Unfortunately, Gagner could not deliver against the best of his peer group in a high-pressure setting. This shows me that he would have consistency issues down the line, or even be a bust (worst case).