Running diagnosis was muscle sprain as there is not much muscle edema visible.
This was misdiagnosis as MRI shows changes in intramuscular fascia/tendon. Injury of that kind is more complex than standard soft tissue-muscle injury as amount of damage does not correspond to level of injury and patient often wrongly access the pain(it is often more felt as discomfort within a week) and return to training too soon, risking repeated injury. On following pictures(better visible in original DICOM form) even on anatomical projection marked with arrow, vagueness/ disappearance of tendon is visible, that clearly corresponds to partial rupture of tendon/fascia.
Injuries like these, even though look like simple sprains, require longer periods of recovery. Additional intake of amino acids (atleasr 1.5grams per kilo of body weight), vitamin C, collagen, vitamins B and D is advised.
Expected time of recovery is personally variable but patient stiffness/not lightness of calf suggests that injury has not healed completely