Cueto 2013 spring training - 6 starts, 5.16 ERA (not sure why you are not counting his last start of 6 scoreless innings on 3/26)
Cueto 2012 spring training - 5 starts, 4.95 ERA
Cueto 2011 spring training - 4 starts, 6.00 ERA
Cueto 2010 spring training - 5 starts, 5.40 ERA
You are literally "a little concerned" over nothing.