Former Romania national team coach Razvan Lucescu signed a one-year contract with Greek Super League side Xanthi on Wednesday while Ricardo Sa Pinto took over at Atromitos.
Lucescu, 45, replaces Sakis Tsiolis who was fired last week with Xanthi in the middle of the table having taken five points in the first four matches of the season.
He coached the Romanian side from 2009 to 2011.
Portuguese coach Sa Pinto, 42, last season coached OFI Crete and before that had stints with Red Star and Sporting Lisbon.
A former Portuguese international, he made 45 appearances for the national team from 1994-2001, scoring nine goals.
Sa Pinto replaces Giorgos Paraschos who had taken Atromitos to fourth position with seven points in four matches but had suffered an early exit from the Europa League.