San Francisco 49ers quarterback Mac Jones warms up before a preseason game Aug. 16 in Las Vegas. (AP Photo/John Locher)

SANTA CLARA, Calif. (AP) — Mac Jones finally gets the chance to start for San Francisco, four years after the 49ers considered drafting him to be their franchise quarterback.

Jones will step in for the injured Brock Purdy on Sunday when the 49ers visit the New Orleans Saints as he looks to spark a career that got off to a promising start with New England before he regressed the past few seasons.

“I’m just blessed to be here and really thankful for the people here who’ve allowed me to get back on track,” Jones said Friday. “Obviously, there’s a lot more to do and got to be ready for this Sunday and go out there and have fun and let it fly. I put in the work, so that’s all you can ask, at least give yourself a chance.”

Jones will have a chance at least for one week and possibly a few more with Purdy sidelined by a toe injury that has him listed as week to week.

Jones has impressed the 49ers since signing a two-year deal in March, and that carried over this week as he ran the first-team offense all week with Purdy out.

“Mac’s been awesome,” coach Kyle Shanahan said. “He’s the same this week as he’s been all camp. Our team really believes in him and our team really enjoys him. He did a hell of a job this week in practice.”

Jones and San Francisco were closely linked leading up to the 2021 draft after the Niners traded three first-round picks to get the No. 3 overall selection. Shanahan was looking to draft a franchise quarterback and was debating between Jones and Trey Lance before San Francisco finally opted for Lance.

The move backfired as Lance struggled to stay healthy and adjust to Shanahan’s system. He made only four starts in two seasons before being traded to Dallas for a fourth-round pick in August 2023, having lost the starting job to Purdy, the last pick in the 2022 draft.

Jones had a strong rookie season in New England but was 4-14 with 16 TD passes, 20 interceptions and a 77.1 passer rating in 18 starts the past two seasons for New England and Jacksonville.

But now he gets another chance to get back to the level he was at in 2021 when he helped the Patriots reach the playoffs.

“I’ve done this a lot of times that doesn’t mean I’ll be great at it one way or the other,” he said. “It just means that I have a schedule and a system that I know that works for me as a starter and got to do that this week.”

Defensive end Nick Bosa said earlier in the week that he believed it was an advantage for Jones that he is stepping in so early in the season because he had recently gotten extensive work in training camp.

Jones said that’s a major difference from last season, when his first start in place of an injured Trevor Lawrence in Jacksonville came in Week 10.

“That’s a great point by him,” Jones said. “Obviously it’s fresh and like last year I didn’t play until, the 10th … game of the year or whatever. Not that you’re rusty, but it’s just a little different.”

Adrian Martinez will be elevated from the practice squad to be the backup quarterback on Sunday. Martinez hasn’t appeared in an NFL game but has spent time in camp with Detroit in 2023 and on the practice squad with the New York Jets last season.

Martinez was the MVP of the UFL in 2024.