McGrotty and Lamb were handed their marching orders after Bracknell lost 3-0 to Marske United in the FA Vase quarter-final at the weekend.
After discovering the news, McGrotty took to Twitter to tell fans that they'd left the club.
After a second-place finish in 2016/17, Bracknell are currently fifth in the Hellenic Premier standings – 20 points behind league leaders Highworth Town, but with six games in hand.
After informing the pair, Bracknell released the following statement: "Yesterday we made the very tough decision to part company with Jeff & Paul. We would like to thank them for their efforts in their short time here and wish them all the best for the future.
"Carl Davies has been appointed Player-Manager until the end of the season and we welcome back Geoff Warner as Assistant Manager. Reserve Team Manager Andy Findlay will take the team to Longlevens tomorrow night in the cup."
Looks like Bracknell's chairman is off the e-card Christmas list for McGrotty and Lamb this year.
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