He was terrible last season
http://www.footballoutsiders.com/under-pressure/2013/under-pressure-mckinnies-woes
You can pull up plenty of gifs of tackles and them getting beat, but anybody watching last year saw Mckinnie clearly aided this team at the LT position. It got worse towards the end but he was an asset for this team and Tannehill when he got here.
That being said, it's just OTA's and Mckinnie doesn't want to sign now anyways. He'll get picked by somebody when camp/preseason starts.