Oldham have signed former Burton defender Tomas Egert.
The 25-year-old Czech has agreed a one-year deal with the option of a further year.
Egert, who made three appearances for the Brewers in the Championship, is fit after missing last season with an anterior cruciate ligament injury.
The centre-half, who began his career with Slovan Liberec in the Czech Republic, has been training with the Latics over the summer to build up his fitness.
His arrival was followed soon afterwards by that of winger Callum Dolan. The Manchester United academy product made four appearances for Altrincham last season.