Brent actually was considered a decent prospect when the Tampa Bay Lightening drafted him 49th overall in 1992. The smaller (5'10" 160lbs) brother came off of a 43 goal, 121 point season with the Ontario Hockey League's Belleville Bulls.
But make no mistake, the Lightening drafted him for the marketing potential just as much as any hockey potential Brent had. In fact, Brent's first call up to the NHL came just days before Wayne and the Los Angeles Kings came to town. It helped to increase ticket sales as not only would the greatest player was coming to town, but for the first time he would face his own brother. The showdown happened on October 20, 1993. For Brent it was just his second NHL game. The Kings won the game 4-3 while Wayne outscored Brent 3 points (1 goal, 2 assists) to 0.
Brent, who would go onto to bounce around with various minor league teams, scored 1 goal and 3 assists in his 13 NHL appearances.
Oddly enough, if you combine the Gretzky brothers NHL career scoring stats, with the obvious majority coming from Wayne alone, the Gretzkys would outscore other famous NHL brother acts such as the Richards (Maurice and Henri), the Stastnys (Peter, Anton and Marian) and the Hulls (Bobby and Dennis). In fact, thanks to Brent's 4 point contribution, the Gretzky's are the highest scoring pair of brothers in NHL history. And if you include Wayne's playoff point totals, the Gretzkys even outscore the 6 Sutter brothers who played a combined total of 90 seasons in the NHL!
Wayne and Brent had another hockey playing brother who would go onto a lengthy and well travelled minor league career. Keith Gretzky was selected 56th overall in the 1985 Entry Draft. Here's more on Keith as well as Wayne's non-hockey playing siblings, Glen and Kim.