Brock Purdy was on the receiving end of criticism after his performance against the Jacksonville Jaguars on Sunday. The four-year quarterback returned to action in Week 4 after missing two straight games with a toe injury. He participated in every practice session and didn't have a designation ahead of the Jaguars duel.The San Francisco 49ers lost 26-21 against Trevor Lawrence and Co., a result that didn't sit well with 49ers reporter Grant Cohn. After the game was over, Cohn, still at the stadium, went on a 2-minute rant against Purdy, calling him out over his turnovers, and said Purdy shouldn't have been on the field against the JAGS."That was gross," Cohn said. "The 49ers just lost 26-21 to the Jacksonville Jaguars and it's hard to blame a loss on one player entirely, but this loss was on Brock Purdy. It was his fault. He threw two picks and fumbled with the game on the line at the end. He still had a chance to win, even though he was so bad, and he fumbled with the game on the line."Yes, he was not healthy. He should not have been playing, but the fact of the matter is, his turnovers had nothing to do with his toe. The first pick, he floated the ball into traffic. It was an awful throw. The second pick was into triple coverage and the fumble, he just got the ball knocked out of his hands. He played like a backup quarterback; he had no mobility, and if you take mobility away from Brock Purdy, he's just Jimmy Garoppolo without the jawline."Brock Purdy went 22 of 38 for 309 yards and two touchdowns. He was intercepted twice and sacked once, while posting a 79.8 passer rating. Purdy ran the ball twice for a 13-yard gain.49ers insider threw shade at Brock Purdy after Mac Jones' game-winning driveIn Week 3, after Mac Jones went 24 of 41 for 284 yards with one touchdown and an interception, Grant Cohn praised the former New England Patriots quarterback for leading a game-winning drive that ended with a 35-yard field goal to beat the Arizona Cardinals and improve to 3-0."Look, I'm not saying Brock Purdy wouldn't have won this game, but Purdy might not have won this game," Cohn said. "He had the ball down by one against the Cardinals last season and threw a game-losing interception. He was not clutch. He threw two picks, Mac threw one pick."This week's performance didn't help Purdy's case with Cohn, as the 49ers drop to 3-1 to start the season.