I'm not as worried about this as you are. That's not a lot of innings for one, and for two, the biggest challenge he had facing hitters as a starter was getting hitters out by contact -- and as evidenced by the fact that those starts were by and large effective for him even without the K ball, he's getting there. Especially because those 18.1 innings represent 3 starts (seriously, do the math).
Bard's line so far averages about a quality start (30 innings over 5 start, ERA just came down below 4.5). He's basically a #3 starter pitching out of our 5 spot. For a guy who has never started successfully professionally before, that's not too freaking bad..