The Boro squad returned to Rockliffe Park on Wednesday after the summer break.
The majority of the squad checked in to Rockliffe Park yesterday for a series of tests and assessments in preparation of pre-season training which starts today.
Yesterday also gave new boss, Garry Monk, a chance to meet his new squad for the first time.
Garry Monk and his backroom staff will lead their first training session on Thursday, having been working hard to ensure Boro's pre season plans are in place.
Some members of the squad have already been through summer training, with George Friend and Patrick Bamford volunteering with some warm-weather training sessions.
However, Boro fans won't be seeing Viktor Fischer feature in a Boro shirt again, having joined Bundesliga side Mainz for an undisclosed fee.
The 23-year-old who joined Boro for around £3.8m last summer made 13 Boro appearances, however he's opted for a move to Germany in a bid to "really enjoy my football again".