The San Francisco 49ers are coming off an impressive win over the Cleveland Browns in Week 5. Unfortunately, it appears they were not able to make it out unscathed.

According to Matt Barrows of The Athletic, left tackle Mike McGlinchey will be out for the next 4-6 weeks after undergoing arthroscopic surgery on his left knee:

Mike McGlinchey injured his knee Monday and is getting his knee scoped. He’s now out 4-6 weeks.

The loss of McGlinchey deals a devastating blow to a 49ers team that had already been dealing with its fair share of key injuries thus far in the 2019 NFL season.

Offensive tackle Joe Staley had already been sidelined with a leg injury and is expected to be out for at least another month. Meanwhile, fullback Kyle Juszczyk is slated to share the same timetable as McGlinchey while nursing a knee injury. As a result, the 49ers will now be without both of their starting backups for the next several games.

The timing of the rash of injuries is hardly ideal for San Francisco. This team has overcome plenty of doubt to maintain its perfect start to the season. However, their flawless record could be in jeopardy against a Los Angeles Rams team that is desperate to get back into the win column in Week 6 following back-to-back losses.

The 49ers offense had been clicking on all cylinders as evidenced by the clinic they put on against the Browns on primetime. They will now be relying on backup tackles Daniel Brunskill and Justin Skule to hold down the fort until the offensive line is restored.