Wes Welker Reunites with Bob Kraft

New England Pats owner Bob Kraft came face-to-face with one of his most famous ex-WRs this weekend, Wes Welker ... TMZ Sports has learned.

Turns out, the two both happened to be dining at Capo Restaurant in Boston (a pro athlete hot spot) on Saturday night -- before the Patriots took on the Dolphins at Gillette Stadium.

We're told the owner of the place told Wes that Bob was dining in another section of the restaurant -- and Wes decided to go pay his old boss a visit.

A restaurant spokesperson tells us both Wes and Kraft left their parties and sat down at their own table -- where they talked by themselves for roughly 30 minutes and drank martinis.

Unclear what they talked about -- but Welker was telling staffers that he was in town to throw with Tom Brady ... which he did.

The next day, Welker went to the game ... dressed in a Tom Brady mask ... and the fans LOVED it.