A lot of these teams struggle to get full teams together. Tough to do with overseas contracts and travel expenses and the time it would require. Not to mention that it is a non-paying job unless you happen to be the 1 team out of 64 that wins it all. These guys will be back and if they add 2 or 3 more guys, they could really make a run. First time in and they were a 5 seed based on their roster of players, so any upgrades would be great.
And another note, any guy gets an injury and loses out on a overseas pro contract, it could be cost them millions. Some likely aren't willing to take that risk.