The phrase "fresh troops" refers to newly arrived soldiers who have not yet seen battle. They are often seen as an advantage because they have not yet been worn down by the stress of war. Some synonyms for "fresh troops" might include "new recruits," "raw troops," or "untested soldiers." Another term that could be used is "green troops," which refers to soldiers who are inexperienced or naive. Alternatively, one might use the phrase "recent arrivals" to describe troops who have just entered the field. No matter the phrase used, the presence of new soldiers can often be a key factor in turning the tide of a battle.