Injuries have kept the heart of Twins offensive corps -- Joe Mauer, Delmon Young, Michael Cuddyer and Justin Morneau -- from playing a single spring game so far, setting a dire tone at the outset of the new season, with Morneau looking for all the world like he will be lucky to return to action at all, let alone before the first official game.

Though Mauer likely can return soon from a rehabilitating knee injection, as will Young from a bout with turf toe and Cuddyer from a common wart excision, Morneau continues to suffer from concussive syndrome resulting from a second base collision at mid-season last year.

Morneau already has missed nearly a full eight months of normal baseball play, leaving doubts as to his readiness even were he to return to the diamond tomorrow. Worse, his return to full play still looks to be days, even weeks, away, with permanent disability a distinct possibility.

Doctors continue to limit his activities while he continues to suffer from headaches, dizziness, nausea, sunshine aversion and other symptoms that only will worsen if he trains too hard before his recovery is complete.

What's especially disquieting about Morneau is that return-to-play medical criteria after a sports-related head injury generally calls for a simple, gradual progression from complete rest to light exercise to sport-specific exercise with a gradual addition of resistance training. That's followed by non-contact training drills. Finally there is limited contact, then full-contact training before a complete recovery can be declared.

Progression through each step, however, is dependent upon the presence or absence of symptoms, and Morneau still continues to have plenty of bad moments, as evidenced by his need to wear dark glasses all the time, even during limited periods of swinging at bat in the cage, reportedly no more than 40 swats at a turn.

There is no science behind these procedures as the strategy is largely based on anecdotal expert group consensus panel recommendations. Typically, however, return to play occurs in one to two weeks after the initial injury. No such luck for Morneau.

Frustratingly, it's just as likely that he would be in the same position even if there were no medical interventions or recommendations. It's surprising how little medical experts understand about the condition.

A recent study from from Pace University in Pleasantville, N.Y. , (Mayers, L., Arch Neurol 65(9):1158, September 2008) reviewed the findings cerebral response following a concussion, better known as traumatic brain injury -- a subject undergoing an ambitious (read: expensive) investigation by military scientists pertaining to injured troops exposed to explosive blasts.

This effort includes the placement of multi-million dollar magnetic resonance imaging machines into remote forward field hospitals to help facilitate both pre- and post-deployment neuropsychiatric testing in for all members of the U.S. military.

Small studies of EEG event-related potential recordings in concussed athletes reported deficits (unrelated to the results of neuropsychological testing) for up to five weeks in both symptomatic and asymptomatic athletes, and for up to 30 months in those sustaining multiple concussions.

A study that assessed motor-evoked responses on transcranial magnetic stimulation reported abnormalities for up to nine months in multiply-concussed athletes, an interesting finding considering Morneau has sustained three concussions, two while playing for the Twins and one while playing hockey as a teenager, a term of nearly a decade.

The results of small studies using highly specialized research techniques suggest that simple concussion produces brain dysfunction, even in asymptomatic subjects, that can persist for at least one month, indicating that safe return to play after concussion might require at least four to six weeks after the injury.

So far, so good, but from time-to-time clinicians see samples of patients that evidently did not read the medical textbooks, whose conditions do not follow the usual pattern of healing and rehabilitation.

It is not too soon to predict that, for all appearances, Morneau is an unfortunate member of this subset, not dissimilar from former Twin's third baseman Kory Koskie, the Giants Mike Metheny and a long list of other athletes who were forced into retirement following a substantive blow to the head.