Tommy John surgery is becoming an increasingly common procedure in baseball these days and isn’t considered to be the potential career-ender that it once was. Still, replacing an elbow ligament typically requires at least a year, and often longer, of recovery and rehabilitation before a pitcher is ready to return to the mound. So it is particularly disappointing when some of the game’s young stars are stricken by a blown elbow, like this past week when it was announced that both Shohei Ohtani of the Angels and Michael Kopech of the White Sox have been recommended for UCL surgery.