Carlisle United manager Greg Abbott has taken four players on a week-long trial at Brunton Park.
Abbott will be monitoring the quartet during the players' first full week of pre-season training.
Patrick Clegg, 24, recently left Hibernian and has also played for Falkirk after starting out at Manchester United, while fellow midfielder Billy Gibson, 19, from Watford impressed during a previous trial in May.
Another teenager, Jake Simpson, 19, won the young player of the year award at Shrewsbury last season before being released and Francois Zoko, 26, a former Ivory Coast Under-23 international, is currently at Belgian side KV Oostende.
Meanwhile, Carlisle are still considering the offer of compensation from Watford over the transfer of Tom Aldred.