Allen will be assisted Trevor Burroughs for Tuesday's visit of Barwell in the EVO-STIK League's top flight after former Stoke City, Burnley and Southampton defender Thomas was relieved of his duties on Saturday night in the wake his side's 4-0 reverse at Altrincham, their ninth of the season.
The heavy defeat left the Pics rooted to the bottom of the EVO-STIK League Premier table, triggering the club's decision to part company with the 38-year-old and his number two Will Ryder less than six months after their appointments in May when Allen stood down from his last spell as manager to concentrate on his duties as chairman.
The Pics, who will start advertising for a successor to Thomas this week - paid tribute to the pair in a statement explaining their early decision to opt for a change with less than a third of the 2017-18 campaign completed.
The statement read: "The club would like to thank Wayne and Will for all of their hard work and wish them all the best in the future. It is not a decision that the club has taken lightly and we are saddened that things have not worked out.
"Sitting at the foot of the EVO-STIK Premier table approaching a third of the way through the season and the manner of recent results has brought this difficult decision into focus and it is one that we feel has been made in the best interests of the club."
UEFA A Licence coach Thomas kicked off his career at Torquay United as a no-nonsense centre-back and commanded a transfer fee of £1 million when moving to Southampton in the summer of 2007.
After making more than 400 appearances in the Football League he played in Non-League at a number of clubs including Worcester City and Tamworth. As a coach, the 38-year-old worked for the academy at the New York Red Bulls and was combining his role in the EVO-STIK League Premier with coaching the U19s at another of his former clubs, Kidderminster Harriers.
Allen, pictured with Salford City co-owner Gary Neville, returned to the managerial hot-seat in May 2016 to take over from Richard Sneekes after originally joining the club as manager two decades ago in September 1997. Before that, he guided the Pics to a tenth-placed finish on their Southern League debut in his last full season in charge in 2005-06 as well as lifting the Staffordshire Senior Cup.
Respected first team coach Burroughs counted Halesowen Town and Sutton Coldfield Town among his former clubs before his arrival in 2015 to assist Allen in his last spell on the touchline.
Image courtesy of www.rofc.co.uk
Follow us: @evostikleague on Twitter | Facebook www.facebook.com/evostikleague