Assuming performances of players are similar, generally speaking, I will not hesitate to sell old Donnelly

Player form and your team goals are important information for decision. If Donnelly is in good form and your team rely on him to get good result and your team's aim is still getting the best competition result, it will be harder to sell him immediately. If possible (you have 7 days to sign), I may select to wait until his performance dropped.

I am also waiting to sign 4 players at this moment.