Guerra was admitted with a blood clot in his right-arm (his pitching arm), and is expected to miss at least 3 months with the injury. It is unclear as to why he was moved into intensive care, and if it is related to any kind of an increased severity.
Guerra was traded to the Twins from the Mets as part of the infamous Johan Santana trade, which ultimately did not help either side reach their ultimate goals. The Twins have struggled to develop pitchers since Santana's departure, and the Mets have not reached the playoffs since 2006.
This is obviously concerning news, and hopefully Guerra can recover from this blood clot and return to play baseball again as soon as possible.
Guerra also missed out on a chance to pitch in the World Baseball Classic for team Venezuela, but obviously the clot prevented him from doing so.
There are plenty of cases of guys who recovered from similar clots and ended up pitching in the Majors again, and it would certainly be fantastic news if Guerra recovers from this as swiftly as possible.