I would hang onto Liriano for a little while longer. If you've come this far and swallowed his ghastly numbers so far, why not wait another few weeks to see what happens?
My own view -- and I've been saying this for months -- is that it is totally unrealistic to expect Liriano to show 2006 form any time soon. If you drafted him with a long-term perspective, then he might pay out for you. But it's an investment and there's risk (a lot of risk).
But whatever you do, you DON'T want think Liriano's any kind of money in the bank and let his 2006 dominance distract you from jumping on some young prospects that are right here and now. Guys like Cueto and Voltron are probably long gone. But keep an eye out for other less-hyped guys like Jon Sanchez (another K/9 machine with control issues) and of course mid-season call-ups like Kershaw. Maybe it's even Homer Bailey's time to shine.
I am the Master. Don't question the Master. Just do what he says and be proud.