Derby announced last week that Lampard had been given the chance to speak to Chelsea, who are willing to install him as Maurizio Sarri’s successor at Stamford Bridge.
Pre-season training at last season’s championship play-off losing finalists begins on Monday but Lampard will not be around to oversee it.
Derby in a statement released early Monday acknowledged Lampard’s imminent takeover at Chelsea while taking the necessary steps to find his successor at Pride Park.
A club statement read: "Derby County Football Club has excused Frank Lampard from reporting back for pre-season training on Monday and Tuesday to allow his discussions regarding a potential move to Chelsea to be concluded as soon as possible.
"The first few days of pre-season training will be focused on fitness training and will continue as planned under the guidance of the fitness, medical, conditioning and sports science teams at the club’s training centre.
"On the assumption that Frank will reach an agreement with Chelsea to become their new manager, the club shall step up its efforts to find a replacement manager."
Lampard’s Derby contract still has two years to run, meaning Chelsea will have to fork out £4m in compensation to acquire the services of their former midfielder.
Lampard spent 13 years as a player at Chelsea after joining from West Ham United in 2001 for £11m and is the club’s all-time top scorer with 211 goals from 648 appearances.
