Tough one...if you think it is the best deal you can get and you think this gives you a shot at putting you over the top I'd do it, but I'd feel better if I was either giving up a slightly lower pick or getting a slightly better pitcher than Cahill.
If Lee or Napoli would be keepers for you then it is pretty good as you get help this year and next.
C - Contreras
1 - Abreu
2 - Cano
3 - Rendon
S - Machado
O - Betts,Marte,Springer,Hanley
U - C. Santana
B - Pederson,Buxton,Meadows
S - Pomeranz, Duffy, Bauer, Wacha
P - Herrera
R - Chapman, Osuna
B - Sonny, Odorizzi, Stroman, Glasnow, Berrios
DL60 - Cobb