49ers injuries: QB Brock Purdy, WRs Ricky Pearsall, Jauan Jennings out for 'Thursday Night Football' vs. Rams

San Francisco 49ers quarterback Brock Purdy is officially out for "Thursday Night Football" against the Los Angeles Rams with a toe injury. Mac Jones is expected to start in Purdy's place. 

Purdy already missed two games -- Week 2 vs. the New Orleans Saints and Week 3 vs. the Arizona Cardinals -- due to his turf toe injury, but he returned in Week 4 against the Jacksonville Jaguars. However, Purdy said he felt soreness in his toe after the Jaguars game, a 26-21 loss. Purdy went 22 of 28 for 309 yards with two touchdowns and two interceptions in last week's matchup.

Purdy hoped to play Thursday despite sitting out of practice on Monday or Tuesday.

"If I can play this game, I want to play," Purdy said, via ESPN. "Obviously, I want to get right and get healthy and everything, but we need to win this game against the Rams. So that's how I'm looking at it."

Brock Purdy injury: 49ers QB felt toe soreness after loss to Jaguars; status for Week 5 vs. Rams up in the air

Cameron Salerno

Mac Jones, 49ers enter 'TNF' with thin group of receivers

Jones, who has been dealing with a knee injury but was active last week and a full participant in practice this week, started two games in Purdy's absence, helping the 49ers get off to a 3-0 start. In his two starts, Jones threw for 563 yards, four touchdowns and an interception with a 66.3 completion percentage.

This week, though, his wide receivers corps will be depleted as Jauan Jennings and Ricky Pearsall will also miss Thursday night's game. Jennings is dealing with injuries to his ankle and ribs while Pearsall has a knee injury. Another wideout, rookie Jordan Watkins, is out with a calf issue. With the 49ers so beat up, the Rams are up to seven-point home favorites at FanDuel.

Pearsall has 20 catches for a team-leading 327 yards this season. Jennings has nine catches for 129 yards and a touchdown. 

The 49ers were already without receiver Brandon Aiyuk, who is recovering from a knee injury, and tight end George Kittle, who hasn't played since Week 1 due to a hamstring injury.

With Jennings and Pearsall out, Kendrick Bourne, Jones' former New England Patriots teammate, Demarcus Robinson and tight end Jake Tonges will be among San Francisco's top receiving options. The team also has Marquez Valdes-Scantling and Skyy Moore on the roster. Bourne has eight catches for 87 yards in three games this season. Robinson, Valdes-Scantling and Moore each have one reception on the year. Tonges has 12 catches for 125 yards and two scores.

The 49ers and Rams both sit at 3-1 heading into Thursday's divisional matchup.