BASEBALL (AL) * Boston Red Sox -- Signed Joe Morgan (manager) to a one-year contract extension through the 1992 season.
* Toronto Blue Jays -- Placed Dave Stieb (pitcher) on the 15-day disabled list, retroactive to May 23. Recalled Bob MacDonald (pitcher) from Syracuse of the International League.
BASKETBALL (NBA) * Denver Nuggets -- Named Tim Leiweke senior vice president.
* Minnesota Timberwolves -- Named Chris Wright vice president of marketing and Len Komoroski vice president of sales.
FOOTBALL (NFL) * Cleveland Browns -- Signed Michael Proctor (quarterback).
* Miami Dolphins -- Signed Andre Johnson, Ken Burton, Bruce Lang and Brian Williams (wide receivers) and Paul McJulien (punter).
* New England Patriots -- Signed Shawn McCarthy (quarterback-punter) and Mike Murphy (wide receiver).
* New York Giants -- Signed Philip Doyle (kicker).
* Phoenix Cardinals -- Signed James Harper (offensive lineman), Steve Lofton (cornerback) and Chris Williams (nose tackle).