Miami Dolphins running back Mark Walton will be suspended four games for violating the NFL's substance abuse and conduct policies, per the Palm Beach Post's Joe Schad on Twitter.

The second-year rusher joined the Dolphins in the offseason after a troubled rookie season with the Cincinnati Bengals. After the Bengals selected the now-22-year-old in the fourth round of the 2018 NFL Draft, Walton was arrested three times on several misdemeanor charges and subsequently waived last April. The Dolphins picked up the 5-foot-10 running back in the spring.

Miami has a difficult job of managing the backfield following Walton's suspension due to the recent Kenyan Drake trade. The Dolphins sent the 25-year-old rusher to the Arizona Cardinals ahead of the NFL's trade deadline last Tuesday. Drake, a third-round pick of Miami from the 2016 draft, spent the first three-plus seasons with the Dolphins before the tanking team sent him on his way to Arizona.

Walton has rushed 53 times for 201 yards this season, appearing in seven games for the formerly winless Dolphins team. He also has 89 receiving yards.

Walton led the Dolphins in rushing yards on Sunday in the team's only win, tallying 29 of the team's lowly 50 yards on the ground. Miami was able to pick up the victory mostly through former New York Jets quarterback Ryan Fitzpatrick, who recorded 288 passing yards and three touchdowns. The Dolphins held the lead going into the second half for the third consecutive week in a row, but this time around held on to win at Hard Rock Stadium.

With Walton suspended, the next man up is second-year running back Kalen Ballage, a 23-year-old fourth-round pick of the franchise from Arizona State.