|Denard Span was cleared by a physician in Kansas City|
after this collision, but now has been diagnosed with
a concussion and whiplash.
I'll assume this is some sort of record, partly because it is far more common now for players to go on the disabled list than it was 50 or even 20 years ago — more common not because the players today are wimpier or more injury prone, but because it's a lot easier for teams to use the DL and because it improves the quality of play for injured players to heal.
I'm not sure when a formal mechanism to replace an injured player temporarily was established. I know there was a disabled list in 1961, because in his diary book of the Cincinnati Reds' pennant winning season (Pennant Race), pitcher Jim Brosnan makes reference to his roommate, Howie Nunn, going on the disabled list. By the time I started paying attention to such things, sometime in the 1970s, there were two disabled lists — a 10-day and a 21-day, and teams could have no more than two players on the 10-day DL. There may well have been a limit on the 21-day DL.
Caps on the disabled list inevitably meant that players played, often poorly, with injuries. (Atlanta's Chipper Jones this week complained that teammate Jason Hayward should be playing hurt; 80 percent of Hayward is better than most players, Jones claimed. I doubt that; I suspect that Justin Morneau is playing at a bit more than 80 percent of his ability, but the missing 20-15 percent is the difference between being a star and his current, readily replaced, level of production.)
About 20 years ago the 10- and 21-day DLs were abolished and replaced with the current standard 15-day DL. There's also a 60-day DL for long-term injuries, which removes the player from the 40-man major league roster (Joe Mauer and Tsuytoshi Nishioka are on the 60-day DL); the seven-day concussion DL (new this year); and two forms of "family leave," a five-day bereavement leave for a death in the family and a three-day paternity leave for births.
The shorter the period of absence, the easier it is for a club to put a player on the DL. That's the reason for the new concussion list, to make it less risky for the team to sideline a player with a concussion. If Span's symptoms clear in another two days, the Twins will still have him back three days later; if they had put him on the 15-day DL, they'd be stuck without him.
Twins from the Opening Day roster to hit the disabled list this season:
Joe Mauer **
*= currently on the 15-day DL
**= currently on the 60-day DL
***= currently on the concussion DL