I think Jennings thought he had a shot, but Lawrie runs like a bull and was already half way down the 3rd base line. The best part about him is he'd run 100% even if that hit came with him on 3rd base.
You never force someone to hit with 2 outs, even if it was Melky you'd still just be giving an out away, unless the batter was the pitcher or something.
The 2nd bat needs to be someone that can get on base, and Rasmus does that better than Lawrie (at least against RHP), nothing wrong with Rasmus there instead of Lawrie.
While I agree that he's very K-prone, Rasmus will get some money in free agency, if we can sign him to a market-value deal then I would welcome an extension.