EDITOR'S NOTE: This is the fourth part of a nine-part series previewing the 73rd annual National Football League draft of college players. Today, the running backs are previewed.

FOXBORO - The question is not whether the Patriots need help in their running game.

It's how good of a running game they need.

Laurence Maroney, entering his third NFL season, gained 835 yards on 185 carries last year, missing three games due to injury. He had three 100-yard games in the regular season and another two in the playoffs - back-to-back 122-yard efforts against Jacksonville and San Diego - which tended to quiet the critics who claimed he didn't have what it takes to be a lead back in the NFL.

As long as the Patriots continue to put up amazing numbers in the passing game, they may not need much more than that Maroney has given them. Throw in a healthy Sammy Morris, who had two 100-yard games before going out with a collarbone injury, another strong season by versatile third-down back Kevin Faulk and the continued solid play of fullback Heath Evans, and Bill Belichick and Scott Pioli may come to the conclusion that the backfield is in good hands entering the 73rd annual NFL Draft, which begins Sunday.

But the Patriots' coach and his trusted personnel lieutenant have always entered drafts looking to improve their team with an eye on the future. The top running backs in this year's draft may be out of their reach at No. 7 in the first round, or not as important to them as other needs, but there's a lot of depth in this year's running back corps - at least 10 worthy of selection in the first 100 picks and plenty more thereafter.

There is some disagreement as to which of the running backs ranks at the top of the list.

Some suggest that it's Arkansas' Darren McFadden (6-1, 222; 4.37 seconds in the 40-yard dash), who's equally adept at running north-south or around ends, but carrying the ball exclusively with his left arm has led to some fumbling problems, and off-field problems have dropped him on some draft boards.

Others suggest it's Oregon's Jonathan Stewart (5-10, 235; 4.48), an imposing physical specimen who has more experience in a spread offense but can still bulldoze people out of his way. A history of injuries, including recent toe surgery, has some personnel people wary.

Somewhere between the two is Illinois' Rashard Mendenhall (5-10, 225; 4.45), a junior and one-year starter whose running style and build have resulted in comparisons to Herschel Walker. Another first-round-worthy back is McFadden's teammate, Felix Jones (5-10, 207; 4.47), who is just as strong and elusive as McFadden, and has skills that resemble Faulk's ability to be an effective receiver out of the backfield.

By the time the Patriots reach their pick in the second round (62nd) and their first of two third-rounders (69th), they should find Texas' Jamaal Charles (5-11, 200; 4.38), Tulane's Matt Forte (6-1¼, 217; 4.52) and East Carolina's Chris Johnson (5-11, 197; 4.29) available to them. Charles and Johnson are speedsters more likely to be threats to the sidelines or as receivers.

Central Florida's Kevin Smith (6-1, 217; 4.58) gained 2,567 yards in 2007, but may not have the bulk to take as many hits in the pros as he did in college. He should be available at the Patriots' second third-round pick (94th), as will be Rutgers' Ray Rice (5-8, 199; 4.46), Georgia Tech's Tashard Choice (5-10½, 215; 4.53), Michigan's Mike Hart (5-8¾, 206, 4.75) and Houston's Anthony Aldridge (5-9, 170; 4.38).

Worthy of consideration later in the draft are West Virginia's Steve Slaton, South Carolina's Cory Boyd, Toledo's Jalen Parmele and Oklahoma's Allen Patrick.

From New England colleges, Boston College sends Andre Callender and L.V. Whitworth into the mix, more likely to be considered as post-draft free-agent signings, along with UMass-Amherst's Matt Lawrence. Teams looking for a fullback on the second day of the draft will find Arkansas' Peyton Hillis (6-0½, 240; 4.69) in the fourth or fifth rounds, quickly followed by LSU's Jacob Hester (5-10½, 226; 4.63) and West Virginia's Owen Schmitt (6-2, 247; 4.79). Auburn's Carl Stewart (6-1, 230; 4.65) could be a sleeper pick at the end of the draft.

TUESDAY: Offensive linemen.