Neil Lennon has been spotted at West Brom's play-off semi-final defeat to Aston Villa on Tuesday night.
The interim Celtic gaffer was in the crowd as the Baggies were beaten on penalties in a result that means they remain in the Championship for next season.
West Brom are also without a permanent manager with Jimmy Shan in caretaker charge since Darren Moore's sacking.
And Lennon was joined by his long-term assistant Garry Parker.
Parker didn't return to Celtic alongside Lennon when the Irishman went back to the club after Brendan Rodgers' exit.
Instead, Lennon has been assisted by John Kennedy and Damien Duff over the past few months.
Parker, who was also a team-mate of Lennon's at Leicester City, has been part of his backroom staff since he first took the Celtic job in 2010.
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He also moved to Bolton with him as well as being his assistant at Hibs before the pair left the club earlier this year.
The pair being spotted at the game has led to Lennon's odds on being the next West Brom boss being cut to 10/1 from as high as 50/1. This makes him fourth favourite behind leader Chris Hughton.
Celtic also currently have Oliver Burke on loan from West Brom.
