There's no official news as of yet, but widespread reports and rumors on Twitter and the like that young German striker Samed Yesil has torn his ACL while playing for the U19s, which would mean a long layoff for a player that seemed to be finding his level after joining the U21s. Best I can find is a fairly reliable source that covers the Bundesliga on a consistent basis, and was the first to report the news a few hours ago
Samed Yesil has torn his ACL on international duty. 6 months before he can think of training, probably won't play before late November. #LFC— Clark Whitney (@Mr_Bundesliga) February 9, 2013
His stint with the senior squad earlier in the season was clearly too much too soon--by the player's own admission, it would be two to three years before he was ready to contribute on a consistent basis, but the failures of the summer transfer window meant that he had to serve in emergency duty in domestic and cup competition. He wasn't terrible, but it was a bridge too far to expect him to have a huge impact so soon.
If the news turns out true--and it's worth reiterating that we really don't know just yet--it's an unfortunate turn, particularly given the slate on offer for the youngsters this spring. Between the NextGen tie with Sporting and the run-in of the U21 Premier League, he'd be getting regular match action in meaningful(ish) matches. If that can't be the case, it's extremely disappointing, and hopefully he's able to make a full recovery from whatever injury he's incurred in a match that means absolutely nothing.