Friday will be a stressful day for the Phoenix Mercury fans as Satou Sabally's injury in Game 3 of the WNBA Finals series has ruled her out for the next game. The Mercury guard walked off the court in the fourth quarter in Wednesday's 90-88 loss after her head collided with Aces forward Kierstan Bell's knee.The German international had dived to collect a rebound with 4:26 left in the game, but unfortunately, she crashed straight into the Bell's knee. On Thursday, ESPN reported that Sabally has been diagnosed with a concussion and is ruled out of the decisive Game 4 on Friday."Phoenix Mercury star Satou Sabally has been diagnosed with a concussion and has been ruled out of tomorrow’s Game 4 of the WNBA Finals vs. the Aces, the team announced," ESPN reported in the caption of their Instagram post. View this post on Instagram Instagram PostThe Aces have dominated the WNBA Finals series from the very first game. Phoenix has failed to find a strong footing in the series and now faces a do-or-die situation. Las Vegas holds a 3-0 lead in the series, and if they win the game on Friday, they would complete the sweep and lift the WNBA championship for the third time in their franchise history.According to Spotrac, Satou Sabally is on a 1-year $215,000 contract. She signed the deal with the Dallas Wings, but she was later traded to the Mercury. The German international has been a key player for Phoenix during their Finals campaign this season.She was one of Mercury's main offensive outlets, who also played good defense when needed. Sabally averaged 16.3 points, 5.9 rebounds, 2.5 assists and 1.3 steals per game this season.Can the Phoenix Mercury survive elimination without Satou Sabally?Satou Sabally has been a key contributor to the Phoenix Mercury's success this season. She fit into coach Nate Tibbetts' system fairly early and was an efficient floor spacer who could get buckets when needed.Losing her right before a win-or-go-home in the series will be a big blow to the Mercury. However, they have the pieces to stretch the series and survive until the German is cleared to come back.DeWanna Bonner will most probably start in Game 4 to fill in for Sabally, and she needs to make use of her experience and step up her game. Bonner was good in Game 3, she scored 25-points and collected 10 rebounds in 31 minutes.The veteran needs to be consistent in the upcoming game and recreate her offensive output to truly fill in for Satou Sabally's absence. Kahleah Copper has been the best player for Phoenix this entire Finals series, and she just needs to remain consistent in the big game and not succumb to the pressure.Lastly, Alyssa Thomas may have to shoulder some offensive responsibilities as well. The Mercury will have the crowd to back them up as they are returning to their home court for the decisive Game 4. The tip-off for the game is scheduled for 8:00 p.m. ET.