OWINGS MILLS, Md. -- Running back Alex Collins proved to be the biggest surprise of the Baltimore Ravens this season, going from the practice squad in Week 1 to the NFL's 11th-leading rusher.

But Ravens coach John Harbaugh was noncommittal when asked whether Collins earned the right to be the starter for next season or if Baltimore will look to upgrade.

"I'm looking to upgrade everything. You know that's how I'm going to answer the question," Harbaugh said. "Alex Collins has proven the fact that he can be a very good back in this league."

Collins became the Ravens' offensive most valuable player, producing big plays with his aggressive running and elusiveness. After getting cut by the Seattle Seahawks at the end of the preseason, Collins signed with Baltimore's practice squad, took over the starting job for good by Week 7 and ran for 973 yards, outgaining Frank Gore, Carlos Hyde and Marshawn Lynch.

He was one of the few consistent playmakers for Baltimore and kept the Ravens in the season finale. In the third quarter, Collins looked like he was being stopped on fourth-and-3 on the left side of the field before reversing his direction to the right and scoring a 17-yard touchdown.

But Collins isn't seen as a workhorse back by Baltimore. The Ravens never gave him the ball more than 20 times in a game (compared to Todd Gurley and Leonard Fournette, who combined to do so 12 times) because they didn't want to wear down a smaller frame back like Collins. There are also other issues with ball security (four fumbles) and catching the ball (three drops).

The Ravens could just be keeping their options open at running back, especially in the draft. Baltimore hasn't selected a running back in the first three rounds since Bernard Pierce in 2012, and the team could be kicking itself after passing on Alvin Kamara and Kareem Hunt last year.

There are a handful of top running back prospects who could land in the second or third rounds: Auburn's Kerryon Johnson, LSU's Derrius Guice, Alabama's Damien Harris and Georgia's Sony Michel.

Collins proved he could be the lead back in a committee situation like last season, when Buck Allen and Danny Woodhead were contributors. While Terrance West isn't expected to return as a free agent, this group will welcome back Kenneth Dixon, who suffered a season-ending knee injury before the start of training camp in addition to getting suspended twice.

"Kenneth Dixon should be right in that conversation," Harbaugh said. "Kenneth has to take care of his business and be ready to go. I see him in here doing it all the time. Heck yeah, Kenneth Dixon is a big part of that conversation."

The Ravens feel much better about their running game than a year ago at this time. Baltimore's ground game went from being No. 28 in 2016 to No. 11 last year.

But the Ravens haven't ruled out adding someone else to improve the rushing attack even more.

"We're going to look to have the best running back group we can," Harbaugh said. "If that means we add a guy, I'm all for it. If it means it's these guys we have, then yeah, I think they're good enough. I'm all for adding a guy in that position, if we get the right kind of guy that can make us better."