You can never have too many good quarterbacks on the roster. The Cowboys learned this lesson the hard way in 2015, when Tony Romo played in four games and the revolving door of replacements -- Brandon Weeden, Matt Cassel and Kellen Moore -- could only muster four wins among them and Dallas limped to a 4-12 record.

Romo is again on the shelf after suffering a back injury during the preseason. The original prognosis was that he would be sidelined 6-10 weeks, and according reports from ESPN and NFL Network, the Cowboys are targeting Week 8 for Romo's return to the lineup.

Of course, rookie fourth-rounder Dak Prescott has exceeded every expectation imaginable, not only leading the Cowboys to a 3-1 start, but he's done it while completing 68 percent of his passes without a single turnover. Not one.

The latest win came in San Francisco on Sunday, when Prescott and the Cowboys overcame an early 14-point deficit. He finished 23 of 32 for 245 yards and two touchdowns -- and did it all without Dez Bryant, who was out with a knee injury.

But Prescott's emergence doesn't change the Romo timetable, at least as far as owner and general manager Jerry Jones is concerned. Jones maintains that Romo gives the team the best chance to win, according to ESPN's Chris Mortensen's latest report, and Jones hinted as much two weeks ago.

"Not necessarily, not necessarily," Jones said at the time, when asked if Prescott's play would allow the Cowboys to be patient as Romo recovered. "Tony's situation, when he's back, will be about whether he's functional. We're a better team. We play better."

Jones continued: "If Tony had been there from the get-go this thing would be simple. Bottom line is [rookie first-round running back Ezekiel] Elliott is impacting the defense, which says everything right there. They know it and we know it. They're stacking it to stop him."

That was certainly the case against the 49ers when Elliott rushed for 138 yards and a touchdown.

For us, there is some danger in breaking up a good thing, but recent history suggests that there's also no guarantee Romo will be able to stay healthy.