The banged-up San Francisco 49ers will again be without two key pieces of their offence on Sunday against the Philadelphia Eagles.

ESPN's Adam Schefter reports that both quarterback Jimmy Garoppolo (ankle) and running back Raheem Mostert (MCL) will miss out on their Week 4 encounter.

Both men picked up their injuries during a Week 2 matchup with the New York Jets at MetLife Stadium. In the days after the game, members of the Niners were critical of the qualify of turf at the home shared by the Jets and New York Giants, the Niners' opponents in Week 3.

Kyle Shanahan's team will again turn to Nick Mullens behind centre.

Mullens, in his third season out of Southern Missouri, starred in the 36-9 win over the Giants, throwing for 343 yards and a touchdown.

With Mostert out of action, the team's running game was limited with Jerick McKinnon the leading rusher with 38 yards on 14 carries and a TD.

In more positive news from the team, star tight end George Kittle expects to make his return this weekend after missing last week with a knee injury.

The Niners (2-1) meet an Eagles (0-2-1) team coming off of a 23-23 tie against the Cincinnati Bengals in Week 3.