The recent good form shown by Carl Martin convinced Crewe boss Dario Gradi that he didn't need to sign a back-up defender.
Prior to the current campaign, the 24-year-old defender had featured only six times for the Railwaymen since joining from Wealdstone in 2009 - missing the whole of last season due to injury - but he has already played six times this term.
And Gradi told the club's official website: "The fitness and form of Carl has solved the problem of me having to go out and get another centre-half in on loan.
"It has been a real bonus to have him and he has done very well.
"We haven't been able to do much work with him over the last couple of years because of his problems with injuries, but he is an intelligent guy and takes things on quickly.
"There is room for improvement but that can come with the work."