To hedge tennis bets during a player's slump, bettors can employ several strategies. First, they should consider betting against the player in matches where they’re significantly favored, as this reflects their decreased performance and can yield better odds. Additionally, placing bets on the opponent who has a favorable matchup or is in better form can mitigate potential losses. Another approach is to utilize betting exchanges where bettors can lay a player (bet against them) to secure a profit regardless of the eventual outcome. Adjusting stake sizes and diversifying bets on other matches or players who are performing well can also help manage risks. Lastly, keeping an eye on the player's injury reports and training updates can provide insights for more informed hedging decisions.