Winning a fantasy football championship comes down to three things: Having a good draft, making sound waiver pickups and free agent adds, and avoiding the injury bug as much as possible. There are probably a few more factors than that (matchup luck, having nothing better to do with your time than read fantasy articles, etc.), but it’s mainly those three things. Well, one of those elements is completely out of your control, and that thing — the whole injury thing — reared its ugly head again this past week. Specifically, two notable Chiefs (Tyreek Hill and Spencer Ware) and a notable Charger (Austin Ekeler, who was already filling in for Melvin Gordon) got dinged up, and all four missed practice on Monday ahead of their Thursday showdown. That puts Kansas City’s and L.A.’s backups and handcuffs among the top Week 15 fantasy waiver wire pickups, and if any are available after waivers clear around 4-5 a.m. ET on Wednesday in ESPN and Yahoo leagues, scroop them up.It’s all about covering your bases and giving yourself options this late in the season, and when key components from the NFL’s highest-scoring and fifth highest-scoring offenses go down, their backups have plenty of potential value — be it to you or your opponents. Our full free agent list has plenty of streaming options for all positions, and while it’s unfortunately a little light at D/ST, you can still find a fill-in if you’re in a bind. The TEs and defenses can be found at the end of the list. If you’re in the market for a new kicker — or are having trouble falling asleep — you can check out our Week 15 kicker rankings. MORE: Full Week 15 waiver wire list | RB handcuff chartIf you have the top waiver claim, you might decide to hold onto it for one more week just in case something bigger happens, but there are several potential starting RBs out there this week (Elijah McGuire, Chris Ivory) in addition to the players mentioned, so make sure to check your opponent’s roster and see if it makes sense to block one of his or her moves ahead of your win-or-go-home matchup.Week 15 Rankings:Quarterback | Running Back | Wide Receiver | Tight End | D/ST | KickerTop fantasy football waiver wire pickups and free agent adds for Week 15Unless otherwise noted, only players owned in fewer than 50 percent of Yahoo leagues considered.Damien Williams, RB, Chiefs. Even if Spencer Ware (shoulder, hamstring) wasn’t banged up, Williams would be worth a pickup after his 12-touch, 30-yard, two-TD showing in Week 14. If Ware is out on Thursday, both Williams and the recently re-signed Charcandrick West could have value against the Chargers, but Williams figures to be heavily involved either way. He has FLEX upside, especially in PPR leagues. (Update: Ware is officially “doubtful” for Thursday’s game.)MORE WEEK 15: Full waiver listChris Conley, WR, Chiefs and Demarcus Robinson, WR, Chiefs. Perhaps we should add the recently signed Kelvin Benjamin to this list, too, but he’s not exactly the type of fast downfield threat Sammy Watkins (foot) and Tyreek Hill (heel, wrist) are. Conley had looked to be the natural fill-in for Watkins, catching 10 of 15 targets for 99 yards and three TDs in Weeks 11 and 13. But it was Robinson who saw more work than Conley last week, catching five of seven targets for 42 yards compared to Conley’s 2-13 line on three targets. We already know Watkins is out, and if Hill is out, both Conley and Robinson will have upside. If Hill plays, we still like Conley to see more work and be a potential WR3. (Update: Hill is officially “questionable” for Thursday’s game and expected to play.)WEEK 15 PPR RANKINGS: Running back | Wide receiver | Tight endJustin Jackson, RB, Chargers. Jackson was a hot waiver pickup last week after his breakout Week 13 game, but he’s still available in 45 percent of Yahoo leagues. He flopped in a favorable matchup against the Bengals last week, only gaining 12 yards on seven carries, but Austin Ekeler (stinger, concussion) is almost a lock to miss Thursday’s game and Melvin Gordon (knee) is no sure thing to be back either. That would make Jackson the only game in town against one of the league’s worst run defenses. To say he’s a “must-own” is an understatement. (Update: Ekeler is “out” and Gordon will be a game-time decision.) WEEK 15 DFS CASH LINEUPS: Yahoo | FanDuel | DraftKingsIan Thomas, TE, Panthers. Since Greg Olsen left early in Week 13, Thomas has caught 14 of 16 targets for 123 yards. Both matchups (TB and CLE) were favorable on paper, and his Week 15 opponent, New Orleans, isn’t nearly as friendly to TEs (though it did allow two TE touchdowns last week). Still, Thomas is clearly part of the Panthers’ offense and will get opportunities in a potentially high-scoring game. You can’t ask for much more if you don’t have one of the four or five top TEs. Carolina has a similar matchup in Week 16 (vs. ATL), so Thomas could have value both weeks.Check out our full Week 15 waiver list for more potential adds, including top RB fill-ins Elijah McGuire and Chris Ivory, breakout WRs, such as DaeSean Hamilton and Tim Patrick, and more.