Def Leppard and Journey's co-headlining tour is one of the biggest rock tours of the year. The trek commenced on May 21 and, for now, Def Leppard will be continuing without the services of guitarist Phil Collen.

Blabbermouth reports that the six-stringer has left the tour due to a family emergency and no particulars have been made available to further explain his absence. Trixter's Steve Brown has been tapped as Collen's stand-in and made his tour debut last night (May 25) in Hershey, Pennsylvania. Brown is no stranger to the band, having filled in for Vivian Campbell in 2014 and 2015 as the guitarist was battling Hodgkin's lymphoma.

The tour is an exhaustive 58-city trek that will blanket North America from now through early October with small breaks built into the schedule. Head here to see if Def Leppard and Journey will be performing near you.

Adding their name to the ever-growing list of bands with signature beers, Def Leppard recently released their first brew, Def Leppard Pale, which came out on May 23. "I'm not sure I'd necessarily be in Def Leppard had it not been for beer," commented drummer Rick Allen.

See Def Leppard in the 20 Highest Selling Hard Rock + Metal Albums in the U.S.