Elton John [ tickets ]'s bout with flu and infection have caused the singer to postpone a few upcoming dates on the most recent leg of his continuing Face 2 Face trek with Billy Joel [ tickets ].

The pair's Nov. 4 and 7 dates in Seattle, and a Nov. 10 appearance in Portland, OR, have been shelved indefinitely after John was diagnosed with what his doctors termed a "serious case" of E.coli bacterial infection and influenza.

According to a notice posted on John's website, "organizers of the events are working to establish new dates," and patrons are being asked to hold on to their tickets for the immediate future while rescheduling details are sorted out.

"He has flu and is absolutely fine," a John spokesman said Sunday (11/1). The postponements come after Joel's own illness forced several cancellations of US shows in July.

If all goes as planned, John and Joel will continue their latest outing together Nov. 14 in Oakland, CA, with shows plotted through the first week of December. Details are included below.

As with their previous concerts together, John and Joel will start each evening by playing a series of duets with twin pianos and trading vocals. The stars will then perform separately before joining once more for the grand finale, according to a press release. The shows are expected to include some of their greatest hits and a selection of rock-and-roll classics.

John and Joel first toured together in 1994, and their most recent "Face 2 Face" outing before this year's affair was a sold-out, 24-date trek in 2003. The Grammy winners are the most successful and longest-running concert pairing in pop history, according to a press release.