Crewe are running the rule over Abdul Osman while winger Michael West has joined from Blue Square Bet Premier side Ebbsfleet.
The Alex agreed a nominal compensation package for the 21-year-old former Fulham youth-team player and he becomes the club's fourth summer signing. Boss Steve Davis has already snapped up defenders Gregor Robertson and Mark Ellis and forward Mathias Pogba.
Davis also revealed the club are making progress on Byron Moore's new contract, adding: "We are very close with Byron. I spoke with his agent on Monday and have had conversations with Byron over the last week. I will speak again with his agent and hopefully we can get something agreed."
Northampton midfielder Osman, who is a free agent following a spell in Greece, is expected turn out in a friendly against Congleton this weekend.
Boss Steve Davis told the club's official website: "Abdul is a player that was here a few years ago and the club were looking to bring him in.
"He likes to play football and get on the ball. He's a very good athlete and he's different to what we've got. We will have a look at him this week and he will have one or two games to impress."