Glasgow prop Moray Low and number eight Johnnie Beattie, Edinburgh flanker Scott Newlands and centre John Houston, and Ulster centre Rob Dewey were all enlisted to supplement the 33-strong party named by Hadden last week. 

Injury and illness meant a number of players were able to take only a limited part in this week’s activities, which began when the squad linked up on Monday. 

Hadden said: “We had a good three days’ training, mainly at Myreside where groundsman Willie Morton has kept their main pitch in excellent condition. 

“We also trained at Spartans on the artificial surface and made the most of some great weather conditions.” 

Hadden is hoping his foreign-based players - who must be returned to their clubs for matches this weekend - arrive back fit. 

He said: “There is an inevitable element within professional rugby of managing injuries, but we’ll all be pleased if Scotland players having to play club matches outside the country this weekend come through unscathed.”