Brian Roberts’ continuing injury saga will take on another chapter today when the Orioles second baseman visits a hamstring specialist in Dallas to determine why he is not responding as quickly as he had hoped after rupturing a tendon behind his right knee April 4. Orioles manager Buck Showalter said Tuesday that Roberts has spoken on the phone with Dr. Daniel Cooper — who operated in November to remove scar tissue from the hamstring of Tampa Bay third baseman Evan Longoria — and Roberts will meet with Cooper face-to-face today. Roberts, who has played just 118 games since signing a four-year, $40 million extension before the 2010 season, started all three games of the first series of the season at Tampa Bay before coming up lame after stealing second base in the series finale. Originally expected to miss between three and four weeks, Roberts began light baseball activities last week, but he was still affected by the injury. “He doesn’t feel like it’s moving at the pace he’s hoping, so he wanted to see [Cooper],” Showalter said. “What I heard is that he started taking some batting practice and he didn’t like the way it felt. ... I think he’s a little frustrated it hasn’t come faster.” Thursday marks the fifth week that the 35-year-old Roberts has been out, but the club has not moved him to the 60-day disabled list yet, which would create another spot on its 40-man roster. “We’ll see if there’s something else, but I’m not looking at it that way,” Showalter said. “I’m still holding out hope that this will get moving. I like the fact that we don’t have the need for a [60-day move] yet.”