When NFL teams sign players to contracts, there is always a certain amount of risk involved. Some of these risks are due to factors on the field, such as the possibility of injuries or a player dipping below their usual level of production. Football is a violent and, often, unpredictable game, so every contract is a gamble to an extent.Off-the-field problems can also play a major role in the risk factors for each individual player. History and patterns of behavior can help a franchise determine the value they want to place on that specific player, but, sometimes, issues can arise, seemingly, out of nowhere.Just because a player has never caused problems in the past doesn't mean they never will in the future. The same can be said for players with questionable pasts who have turned things around and become much more reliable.Off-the-field issues are always weighed up by NFL teams and can determine whether or not a player will get a big contract. Players have, sometimes, made bad decisions and life choices that have cost them huge paydays in the NFL. Here are five such instances:#1 Aldon SmithOakland Raiders EDGE Aldon SmithAldon Smith was one of the most dominant pass rushers in the league across his first three seasons with the San Francisco 49ers. He managed a massive 42 sacks in his first three years and was selected as a first-team All-Pro.Ian Rapoport@RapSheetFrom NFL Now: The #Seahawks are signing pass-rusher Aldon Smith, a low-risk, high-reward addition similar to the kind that has paid off for Seattle for years.62377From NFL Now: The #Seahawks are signing pass-rusher Aldon Smith, a low-risk, high-reward addition similar to the kind that has paid off for Seattle for years. https://t.co/6uMt8ZUghpSmith struggled with substance abuse, accumulating three DUIs with the 49ers before they released him during his fourth season. He later signed with other teams on relatively small contracts, but missed out on a massive payday, considering pass rushers are the second-highest paid players in the NFL.#2 Adam "Pacman" JonesCincinnati Bengals Adam "Pacman" JonesAdam "Pacman" Jones was once one of the most dynamic defensive backs in the league. Across his first two NFL seasons, he recorded four interceptions, one of which he returned for a touchdown. He also accounted for four additional punt return touchdowns.But his career has been plagued by both on-field and off-field issues, including substance abuse and assault. He was suspended and fined multiple times, adding up to more than two million dollars, and missed out on signing a contract that his talent was capable of receiving.