"Mark played two games for me last season at Workington and I know what he can do. Lee, who has played for Carlisle and Torquay, proved his worth in the couple of matches he has figured in so far. I am delighted to make both deals permanent."
While the pair's arrival has not caused any surprise at Kingston Park, the departure of David Nicholls and ex-Carlisle defender Derek Townsley has. The two players were signed from Gretna during the close season and were expected to be central to Blue Star's campaign.
Cassidy said: "I have let the two lads go, which I think was in the best interests of the club and the players. There will be more comings and goings in the near future. I am putting down a marker for what I want and already things are starting to take shape, even though we lost to Newcastle Benfield Bay Plastics in the FA Cup last Saturday.
"I have said from day one that I am here for the long term. I am getting down to the job, hopefully putting together a squad which will compete. We had real difficulties with injuries last Saturday and I had to make two substitutions at half-time. Hopefully, I will have a full squad to choose from."
Andrews came through the youth ranks at Carlisle before turning professional in the summer of 2001. The 24-year old making 107 starts and 14 substitute appearances for the Blues in a five-year spell before he was released by then United boss Paul Simpson in June 2006.