Today, Andy Martino of the Daily News tweeted that he had "heard" Bobby Parnell would be the first choice for a spot start if Johan Santana needed extra rest.  He then tweeted a clarification that Parnell would be the first out of the pen in a bullpen game (a game in which multiple relievers throw 2-3 innings).There is a lot of speculation in this report, and it's not clear who Martino's source was.  Terry Collins?  Bob Geren?  The assistant clubhouse attendant?However, this is an idea that shouldn't be immediately dismissed.  Parnell has not had success in the past as a starter (1-5, 7.93 ERA, 1.90 WHIP), but his experience came in 2009.  He was a two-pitch pitcher at the time, and didn't have much of a slider.  This Spring, he has developed a knuckle curve, taught to him by Jason Isringhausen, and has throttled back the velocity of his fastball in exchange for better command.  Sandy Koufax also advised him to work up and down in the zone, as opposed to just in and out.  The results have been impressive.Parnell has not allowed a run in 9.1 Innings Pitched, walking 2 and striking out 8.  It's a small sample size.  It's Spring Training.  But a statistical turnaround this drastic from last year (and the year before) is hard to ignore.Parnell, now with 3 pitches, is better suited to multiple-inning outings than he was in 2009, or any year since.The question remains, is he the ideal choice to get a spot start, even if it's a 3-inning appearance?  Miguel Batista is the most suited bullpenner to be a spot starter.  In addition, Closer de Facto Frank Francisco, who has been lit up all spring, is about to get an MRI on his knee.  Wouldn't Parnell be more valuable as a set up man to Jon Rauch or Ramon Ramirez?If Francisco loses any time, the answer is yes.  If not, spot-starting Parnell is not such a crazy idea.