49ers rule WR Mike Evans out vs. Cardinals with rib injury; Trent Williams leaves game on a cart

The San Francisco 49ers lost two more key players to injury against the Arizona Cardinals on Sunday.

Mike Evans left the game in the first half with a rib injury and was eventually ruled out. All-Pro left tackle Trent Williams then left in the third quarter on a cart with with a stinger. The 49ers initially listed Williams as questionable , and further details of his injury were unclear.

Evans ruled out; long-term status unclear

Evans was in clear pain and clutching his right side after running a route in the second quarter. He wasn't hit on the play, but needed the attention of medical trainers as he walked to the sideline.

Trainers then helped him as he walked gingerly on the sideline, and he eventually took to one knee, in obvious pain.

On the play before, Evans took a helmet to his left sight on a tackle by Budda Baker . It's not clear if that hit was related to Evans' injury.

Evans rode to the locker room on the back of a cart late in the first half and was ruled out before the start of the third quarter .

The 49ers didn't provide the precise nature of Evans' injury. He reportedly has a rib strain and will be evaluated further on Monday, per NFL Network's Ian Rapoport .

Another injury blow to 49ers passing game

The injuries are unwelcome for a 49ers team that's been beset by injuries, particularly at wide receiver. Starter Ricky Pearsall is out for the season after undergoing preseason surgery to repair a damaged PCL. Standout rookie De'Zhaun Stribling is expected to miss roughly 10 weeks with an ankle injury sustained in San Francisco 's Week 1 win over the Los Angeles Rams in Australia.

Demarcus Robinson is on injured reserve with a high-ankle sprain sustained in Week 2's win over the Miami Dolphins . Christian Kirk has been on injured reserve since the preseason with a lingering calf injury.

Evans joined the 49ers in the offseason after 12 standout seasons with Tampa Bay and immediately slotted in as their No. 1 option. With Evans sidelined alongside Pearsall and Stribling, the 49ers will rely even more in the passing on Deebo Samuel Sr., tight end George Kittle and running back Christian McCaffrey in addition to backups Kaelon Black, Jordan Watkins and Jacob Cowing .