"Felix Jones' "What I did during the lockout" essay was short and sweet.

"I spent time in the weight room and stayed on top of things (mentally)," the Dallas Cowboys running back said.

Judging by his performance so far in the preseason, he excelled at both.

"I've never seen him more explosive or quicker," quarterback Tony Romo said of Jones. "He also has taken it up a notch with his understanding of the game."

In Sunday's loss to San Diego, which had the NFL's top defense last season, Jones had 56 yards on seven carries. That gave him 79 yards on 10 attempts for the preseason, a robust 7.9-yard average that is an indication the Cowboys (1-1) might finally have something that their opponent tonight, the Minnesota Vikings (1-1), have enjoyed the last four seasons in Adrian Peterson — a true lead back.

"Felix clearly will be the No. 1 back for us," said coach Jason Garrett, who is expected to treat the 7 p.m. game as a dress rehearsal for the regular season and play the starters at least a half and possibly more."