Looking for the best players to target on the waiver wire this week? Well, the Fantasy Ticker is just the place for that. Here are the top pickups for Week Eight, as well as a key player to trade for and one you might want to quickly unload.

HOT PURCHASES

These players should be free agents in many leagues. Pounce on them if you can.

Cardinals RB Beanie Wells (owned in 32 percent of Yahoo! leagues)
It took longer than most expected, but Wells finally delivered the type of performance that made him a popular sleeper this summer. Getting a chance to handle the bulk of the workload over Tim Hightower, the 2009 first-round pick ran for 67 yards and a TD on 14 attempts against the Giants, adding three catches for 10 yards. While not a monster statistical outing, Wells looked impressive, running hard and slipping tackles to the tune of 4.8 yards per carry. The Cardinals won't run the ball enough for Wells to be a stud this season, but he'd have nice value as a flex player if he remains their primary back.

Jets RB Shonn Greene (18 percent owned)
All it takes is one injury for a guy's fantasy value to skyrocket, and that's exactly what happened this week to Greene. After barely playing the first six weeks, the third-round rookie was called into duty early Sunday when Leon Washington went down with a leg injury, which it turns out will be season ending. Greene responded with a huge effort at Oakland, picking up 144 yards and two scores on 19 carries. Although Thomas Jones remains the Jets' starter, New York wants to keep him fresh by divvying up carries, meaning Greene should see his fair share of touches each week. With many favorable matchups in the second half, the Iowa product could be a fantasy difference maker.

Saints RB Mike Bell (33 percent owned)
Recommended as a waiver-wire pickup earlier in the season, Bell was dropped by most owners when he suffered a knee injury that sidelined him for two games. Well, he's back, and he has been the Saints' best fantasy RB since returning. In the two weeks he has been back, Bell has 27 carries for 114 yards and a TD, while Pierre Thomas has 23 attempts for 102 yards and zero scores. Even though Bell and Thomas likely will split carries fairly evenly going forward, Bell seems to be the preferred option at the goal line, giving him definite value in an extremely prolific offense.

Steelers WR Mike Wallace (21 percent owned)
One of the fastest receivers in the league, Wallace won't catch a lot of passes, but he'll make his receptions count. The rookie has been a pleasant surprise for the Steelers this season, emerging as their No. 3 wideout and primary deep threat. With three grabs for 72 yards and a TD on Sunday against Minnesota, he now has 21-368-2 on the year, an average of 17.5 yards per catch. He's not much of a PPR option, but Wallace has had at least 47 yards in each of the past five games, so he has become a consistent weapon for QB Ben Roethlisberger.

BUY LOW

Here's a player who has underperformed thus far and seen his value drop. Trade for him before it's too late.

Lions WR Calvin Johnson
Although many expected a slow start from Johnson as he developed a rapport with rookie QB Matthew Stafford, that actually didn't turn out to be the case, as the stud wideout had a solid first four games. However, after missing most of Week Five with a knee injury, sitting out the following game and then going on bye, it has been a few weeks since Johnson has had a big outing. That might have his owners down on him, making it the perfect time to pounce. The Lions have quite a few nice matchups coming up, starting this Sunday vs. the Rams, and Stafford should return from his own knee injury soon. That makes Johnson a prime candidate to take off in the second half.

SELL HIGH

Deal this guy for productive players now, because his value is about to fall off.

Dolphins RB Ricky Williams
It has been a tremendous season so far for Williams, who hasn't looked anything like a 32-year-old as he has run through tackles and juked defenders. But his game Sunday is as good as he can get from a fantasy standpoint. Carrying the ball nine times against the Saints, Williams ran for 80 yards and three TDs, easily outproducing backfield mate Ronnie Brown. However, 68 of his yards came on one run, so he wasn't terribly effective on his remaining attempts, and it just so happened that he got most of the goal-line work in this one. Most weeks, Brown not only will handle the majority of the carries but also will be in there around the endzone, limiting Williams' value. Try to get as much as possible for the veteran back before he soon comes down to earth.