Nimmala is generally top ranked of Jays prospects.
RT has reliever written all over him. The last few years he's pitched about 40 and 20 innings, respectively, and even with that he can't stay healthy. The chance RT is able to successfully stretch out and be a durable SP is getting rather low.
Yesavage would catch their interest for sure, but no pro innings, and pitchers have more variability in results than position players. Which is why you typically don't see many pitchers taken in the 1st round of drafts.