The pair quit Mansfield with the club sitting fifth in the table, two points adrift of an automatic promotion spot.
On the back of a run that has seen the Stags collect 16 points from a possible 21, Evans has dealt them a major blow in their attempt to win promotion by departing with immediate effect, amid rumours that he is wanted by Peterborough United a division above.
Chairman John Radford told the club's official website: "Whilst I am disappointed by their decision, there are no individuals bigger than Mansfield Town Football Club and the process of appointing a new management team which can lead the club to League One is already underway.
"Mansfield Town Football club has progressed year-upon-year in recent seasons both on and off the field. The club has a fantastic, encouraging and vociferous fanbase; a loyal, patient and supportive board of directors and a dedicated and hard-working team of behind-the-scenes staff.
"With this in mind, along with our current healthy standing in Sky Bet League Two, the vacant post of manager at One Call Stadium is surely one of the most attractive in the English Football League.
"Our ambitions of promotion this season remain as fervent and steadfast as ever and we will leave no stone unturned in our process of appointing the right manager to lead our talented squad of players."
Evans, formerly of Crawley Town, Rotherham United and Leeds United, had been in charge at the One Call Stadium since November 2016.