TEMPE, Ariz. -- The Arizona Cardinals were in a precarious position this week.

They needed a quarterback -- desperately -- since they didn't have one under contract for 2018 heading into the legal tampering period Monday afternoon that precedes the start of free agency on Wednesday. They wanted a veteran. They wanted someone who could win now. They wanted someone who could get a fledgling offense back on track.

They ended up with Sam Bradford.

But which quarterback will the Cardinals be getting when Bradford signs a one-year contract worth $20 million with $15 million guaranteed with an option year?

Only time will tell.

When he's healthy, Bradford can be quite good despite a 34-45-1 career record. He's a career 62.5 percent passer with a 1.77 touchdown-to-interception rate. He has a touch that can't be taught and the ability to make this year's Cardinals offense, based around running back David Johnson and wide receiver Larry Fitzgerald, a contender in the NFC West. He could also be the ideal quarterback to mentor and help groom a rookie for the future.

In short, he could be the perfect bridge quarterback for a team that'll pick No. 15 overall in April's draft. And if the Cardinals want him back in 2019, they'll have the ability to exercise an option on his contract for another $20 million.

Of course, that's all contingent on whether Bradford can stay healthy. And that's a big if.

No, make that a massive if.

The Cardinals risked $15 million guaranteed on a set of knees that might not make it to midseason. Bradford has missed 48 of a possible 128 games in his career -- the equivalent of three complete seasons. He missed the entire 2014 season with an ACL injury, a year after missing nine games in 2013 with an ACL injury to the same knee. He also missed 14 games in 2017.

The last time Bradford was healthy for nearly an entire season, he was one of the most efficient quarterbacks in the NFL.

In 2016, while playing 15 of 16 games for the Minnesota Vikings, Bradford led the NFL with a completion percentage of 71.6 while throwing for 3,877 yards and 20 touchdowns against five interceptions despite going 7-8 as a starter.

Entering 2017, expectations were high. Bradford looked like he was back.

He bolstered his case in Week 1 last season when he threw for 346 yards and three touchdowns while completing 84.4 percent of his passes in a 29-19 win over the New Orleans Saints.

However, amid his impressive showing, Bradford suffered a noncontact injury to his left knee -- the same knee in which he has torn his ACL twice. Fate struck again. He played just one more game the rest of the season, which he finished on injured reserve.

The Cardinals have weighed risk versus reward before with players and contracts, but this might end up being incomparable. First, Bradford needs to get through his physical with the Cardinals so the team doctors and trainers can evaluate that oft-injured left knee. The upside is there wasn't any structural damage from his most recent injury; it has since been scoped and cleaned out by renowned orthopedist Dr. James Andrews. The downside is it's the same knee that has been injured four times, if the aggravation last season in Week 5 is counted.

The Cardinals didn't give Bradford $15 million guaranteed to be a backup. He's their guy. He'll be the penciled in starter, the man the Cardinals and new head coach Steve Wilks will rest their 2018 hopes on.

He's the guy they took a risk on.