I think its just a standard Minor League contract that must be tendered.
For example:
The source said that the Nats have had an ongoing dialogue with Strasburg's adviser, Scott Boras, but have made no offer other than the mandatory minor league tender that all clubs must make to their picks within 10 days of the draft. That is a standard minor league deal that pays the player $1,000 per month but does not include any bonus money.
http://sports.espn.go.com/mlb/news/story?id=4346344