Medical issues continue to shake up plans for Elton John and Billy Joel, who today announced more drastic changes to their Face 2 Face Tour itinerary.

Earlier this month, the co-headliners postponed five concerts. A majority of those changes came as a result of John's hospitalization due to a serious case of the flu and an E. coli infection. However, unspecified "medical reasons" are now preventing Joel from touring.

Throughout the day, John's official Web site has made mini-announcements of postponed and rescheduled performances, as well as a single cancellation.

According to those updates, four upcoming concerts have now been rescheduled, in addition to one previously postponed date. Original tickets will be honored for all rescheduled concert dates.

The most recently affected engagements are tonight's November 20 show at Energy Solutions Arena in Salt Lake City, UT; a November 22 show at Pepsi Center in Denver, CO; a November 25 concert at the Ford Center in Oklahoma City, OK; and a December 1 show at Sprint Center in Kansas City, MO. Those shows are now slated for February 19, February 22, February 25, and February 27, respectively.

Of the five previously postponed events, only a November 10 concert at the Rose Garden Arena in Portland, OR, has been rescheduled. It will now take place February 10. Rescheduling details are still forthcoming for concerts postponed from November 4 and 7 in Seattle, WA; November 14 in Oakland, CA; and November 17 in San Jose, CA.

In addition to the rescheduled performances, a concert booked for November 28 at Verizon Arena in Little Rock, AR, has been cancelled. Scheduling conflicts have prevented John and Joel from rescheduling this performance. As a result, ticket holders can receive refunds at the point of purchase.

As of 4:30 p.m. (ET) on November 20, there have not yet been any announcements about events booked for December 4 at HSBC Arena in Buffalo, NY, and December 7 at Times-Union Center in Albany, NY.