It doesn't really come as much of an immediate surprise, simply because the credible other candidates, such as Tyler Skaggs and Zeke Spruill, were gradually crossed off the list as they started for the Reno Aces over the past few days. But it is still something of an expected choice, on a couple of levels. Firstly, while it's close to the ultimate small sample size, Delgado's previous appearance at the big-league level didn't exactly seem to have him marked out for greatness. A brief call-up to help out the bullpen, led to one appearance for a two-inning stint, which resulted in four hits and a two-run home-run. Additionally, it's not like his Reno numbers have been any great shakes either:
In fact, he has the highest ERA of any of the five candidates: only new arrival Nathan Adcock has put up worse numbers overall this year, at 6.92. It's not even as if the Marlins are particularly vulnerable to right-handed pitching, which might have explained why the team opted to stay away from Skaggs: their OPS against RHP is basically identical compared to when facing left-handers(.617 vs. .625). However, the good news is that, if things don't go as planned, Josh Collmenter will likely be fully rested, not currently having pitched since he threw two innings against the Dodgers on June 12.
I imagine the team are likely hoping for a repeat of what happened when Delgado last faced the Marlins, when he was a Brave, on June 6 last year. Then, he allowed one run and only two hits, as he pitched into the seventh inning, striking out a season-high seven batters in one of his best starts of the season. But, to me, it would seem that is more than countered by the mediocre numbers in Reno, compared to the other possibilities. I'll be curious to hear Kirk Gibson's explanation for the move, when he talks to the media later this afternoon.