Samardzija career: 633 IP, 103 ERA+, 3.80 FIP, 1.321 WHIP, 8.5 K/9, 2.35 K/W
Player X through same age: 818 IP, 101 ERA+, 3.96 FIP, 1.428 WHIP, 9.0 K/9, 1.58 K/W
Player X is Randy Johnson. Now, while I am comparing the numbers, I'm clearly not saying it's going to turn out like that, but sometimes those big guys seem to take a few years to figure things out, not to mention Samardzija lost development time to football.
If the cost isn't too high, I'd take a shot at him. Someone wouldn't go get him for Workman? Man, I'd pack his bags and pay for the ticket.