The San Francisco 49ers announced on Friday that they have signed Alabama linebacker Reuben Foster to his rookie contract. The 49ers traded up into the bottom of the first round to select him at No. 31, netting them a guy they ranked third on their big board.

All draft picks get a four-year contract, while first round picks have a fifth year option. However, one other difference that happens just within first round picks is in fully guaranteed money. Picks on the higher end of the first round generally get a contract that has all four years fully guaranteed. Picks in the back end of the first round get some fully guaranteed money, but not usually into the fourth year.

It would appear Reuben Foster is an exception. In reporting on the deal, NFL Network’s Ian Rapoport said that the deal includes, “a series of guarantees that extend into the fourth year of his deal.” Jason Hurley will keep an eye out for specifics, but according to Jason, fourth year guarantees would appear to be unprecedented for someone selected No. 31 overall since the current CBA was negotiated.

Jason tweeted that fourth year guarantees never happen with pick No. 31. We don’t know how much Foster got in fourth year guarantees, but even $1 would appear to be a first. I don’t have all the numbers in front of me, but in looking back at the rookie deals for the past six years at No. 31, it would appear to be the case. Here are the Over The Cap pages for pick No. 31 dating back to 2011. I use 2011 because that is when the current rookie wage scale was put in place.

Vernon Butler

Stephone Anthony

Bradley Roby

Travis Frederick

Doug Martin

Cameron Heyward

For each player, guaranteed base salary is listed in parenthesis below the base salary. Butler, Anthony, and Roby are all still on their rookie deal, and not into their fifth year option. You see no italicized base salary for year four. Frederick, Martin, and Heyward have all since signed some kind of contract extension. Frederick’s fourth year shows italics for guaranteed base salary, but that was guaranteed with his contract extension, not on his rookie deal.

Foster was projected as a high first round pick entering the draft process, but a torn rotator cuff, a failed drug test, and a heated exchange with a medical person at the Combine all led to him slipping. It leaves me curious as to the negotiation process with the guarantees.

Back in May, Peter King published an article title 24 Hours ... With John Lynch. In it, he followed Lynch around all through the first day of the draft. The 49ers had a wild day one, with their move down from No. 2 to No. 3, and then their move up to No. 31. The 49ers were not sure if the Chicago Bears might take Solomon Thomas at No. 2, but if Chicago did that, the 49ers were prepared to take Reuben Foster at No. 3. King reported that the 49ers had assurances from Foster’s agents about contract contingencies if they picked him at No. 3.

If they pick Foster at three, the Niners have some assurance that the agents for Foster will put contingencies in the contract to cover some of the off-the-field risks he presents. Foster tested positive for a diluted drug sample at the scouting combine, meaning there may have been an attempt to drink enough water to hide a positive drug test. And Foster flipped out on a hospital employee over the extended wait for combine medical tests in March; he was expelled from the combine for that. “They [Foster’s agents] are all in on that if we pick him up here,” Lynch says.

I don’t know if we’ll ever find out the full details, but I’m fascinated to know what potential contingencies the 49ers deal has with Foster having picked him at No. 31 instead of No. 3. And considering they included what seem to be unprecedented fourth year guaranteed money, one has to wonder if there are any sort of contingencies in place for the rest of the contract. Paraag Marathe has proven himself to be a great contract negotiator. Rookie deals are not overly complicated compared to veteran free agent contracts, but Foster’s might be a bit more complicated than your average deal.