I have read an older post of Stepenwolf about that thing and I tried it twice. This season I sign with a back-up player the 4th day, after the beginning of the league but I get also a 2 years contract. I don't think you can renew a contract for 3 years. If someone has an example please post.

1st day
Click image for larger version.  Name: sign DIDI .jpg  Views: 40  Size: 50.2 KB  ID: 38341

4th day
Click image for larger version.  Name: sign HULK 2-12.jpg  Views: 39  Size: 47.8 KB  ID: 38342

the same, 2 years.