I have 7 x 4 x 3mm tear in the subscapularis & mild calcific tendonitis of the tendon--will this need surgery?

It depends: The decision of whether to do surgery on the rotator cuff depends on many factors: 1) level of pain 2) loss of function 3) success of nonsurgical treatments 4) patient's age 5) occupation and a few others. This would likely be considered a partial tear. Nonsurgical treatment could include anti-inflammatories, relative rest, physical therapy and various types of injections.

Tear: There is a chance that can heal without surgery. You also need to know from the MRI if this is a complete or partial tear which can change the outcome.