Midfielder Barnett was among a much-changed Salop side which was knocked out of the Trophy on penalties at Port Vale.
The 19-year-old scored from the spot in the shoot-out, which Town lost 4-3 after drawing 1-1 in normal time, becoming the club’s youngest-ever player to net from 12 yards.
His inclusion came as a blow to Telford, who are aiming to reach the National League North play-offs, as they were due to have him until March, after extending his initial one-month spell.
But they are seeking to seal a new loan deal which will see him return to the New Bucks Head for the remainder of the season.
Barnett has made four appearances for Salop this campaign – one in League One, three in the Trophy.
He had played eight times in National North for Gavin Cowan’s Bucks – four as a starter, four as a substitute. He also scored in the 4-3 FA Trophy win against Farsley Celtic.