One of the most disappointing running backs in fantasy football over the first four weeks has been Jay Ajayi of the Miami Dolphins. He's only played three games, but in PPR leagues, Ajayi is currently the 46th-ranked running back on the season.

He did not help his cause over the last two games, scoring a combined 10 fantasy points against the New York Jets and New Orleans Saints. Ajayi's fantasy stock is as low as you'll ever see as a healthy player.

Ajayi owners should stay put and hope he can put up a good performance. When he does, sell and get what you can get for him. Selling right now won't get you a fair return. If you can get Doug Martin, who is making his 2017 NFL debut this Thursday against the New England Patriots, do it.

Ajayi could be a buy low option but there's too much risk involved. The same can be said for Melvin Gordon, but it's a risk you should be willing to take.

MELVIN GORDON, RB, Los Angeles Chargers

Gordon only has 3.1 yards per carry this year, and that shouldn't surprise anyone as he has a career 3.7 mark over 31 NFL games. It's the touchdowns we love from Gordon. He had 10 last season and has two in his first four games. Gordon finished tied for third with 50 red zone rushing attempts last season, three behind David Johnson for second. That's impressive because Gordon missed his last three games of the season. The goal line touches should continue to be his and you can't say that about a lot of backfields in the NFL as many continue to be crowded. Gordon still managed to play 42 snaps last week against the Philadelphia Eagles, so even if he isn't feeling 100 percent that's a huge plus that he's still getting plenty of playing time. The way to attack the Eagles is through the air. Don't worry about last week's performance, Grab Gordon while you can.

JOE MIXON, RB, Cincinnati Bengals

There's been so much hype around Mixon this season as we are all just waiting for him to explode. It remains to be seen and owners have to be disappointed with his performance against the Cleveland Browns. He did not have a good day, but he again had more touches and snaps than Jeremy Hill and Giovani Bernard. It's clear he's the No. 1 back in Cincinnati and there is still an opportunity to buy low. Enough hasn't been said about the loss of Andrew Whitworth on the offensive line, but Mixon has been involved in the passing game as well. He has seven catches in his last two games and has caught all 11 of his targets.

AMEER ABDULLAH, RB, Detroit Lions

Abdullah has yet to have a game in his career where he runs for 100 yards. He came close last week with 94 while finding the end zone, but there's still reason to be concerned. It was only his third rushing touchdown in 22 career games. Abdullah is one of four backs who have at least 14 rushing attempts in each game (Lamar Miller, Leonard Fournette and Todd Gurley). Something has to be said for the usage, but keep in mind, Abdullah has had two major injuries in two NFL seasons. He also tweaked his ankle last week, but should be fine to play this week. It is also a crowded backfield in Detroit and a pass happy team. You can't ignore the fact that Dwayne Washington has four rushing attempts inside the red zone and this is a team that likes to use Theo Riddick. Sell Abdullah now and see what you can get for him.

___

This column was provided to The Associated Press by the Fantasy Sports Network, http://FNTSY.com