I think they can get the 4th year back for JSmith if he spends the season on the NFI
Section 1. Accrued Seasons Calculation: (a) For the purposes of calculating Accrued Seasons under this Agreement, a player shall receive one Accrued Season for each season during which he was on, or should have been on, full pay status for a total of six or more regular season games, but which, irrespective of the player’s pay status, shall not include games for which the player was on: (i) the Exempt Commissioner Permission List, (ii) the Reserve PUP List as a result of a nonfootball injury, or (iii) a Club’s Practice Squad.
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Section 3. Nonfootball Injury: (a) A player who is placed on a Nonfootball Injury or Illness list (“N-F/I”) will not be entitled to any compensation under his contract while on such list but, except as provided below, his contract will continue to run while in such status. (b) A player on N-F/I who is in the final year of his contract (including an option year) will have his contract tolled. However, if the player is physically able to perform his football services on or before the sixth regular season game, the club must pay the player his negotiated Paragraph 5 Salary (pro rata) for the balance of the season in order to toll such player’s contract. If such player is taken off N-F/I during the period when such action is allowed by League rules, his contract will not be tolled.
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Section 2. Credited Season: For purposes of calculating Credited Seasons under this Article only, a player shall earn one Credited Season for each season during which he was on, or should have been on, full pay status for a total of three or more regular season games, but which, irrespective of the player’s pay status, shall not include games for which this player was on: (i) the Exempt Commissioner Permission List; (ii) the Reserve PUP List as a result of a nonfootball injury; (iii) a Club’s Practice or Developmental Squad; or (iv) a Club’s Injured Reserve List.
https://nfllabor.files.wordpress.com/2010/01/collective-bargaining-agreement-2011-2020.pdf