Injuries to Mostert, Garland likely to shelve them for weeks

The losing streak is over, but the injury news continues.

The excitement of the 49ers’ musthave 2416 win over the Rams on Sunday was muted a bit by the dayafter medical report: Running back Raheem Mostert suffered a high ankle sprain, center Ben Garland has a calf strain, and both are expected to go on injured reserve and miss at least three games.

In addition, former Pro Bowl left tackle Trent Williams is dealing with an ankle sprain and head coach Kyle Shanahan indicated he had an MRI on Monday to determine the severity. Finally, strong safety Jaquiski Tartt has a groin strain. It’s not clear whether Williams or Tartt will play Sunday, when the 49ers visit New England.

The loss of Mostert after the 49ers’ first offensive play of the second half was a reason the offense stalled after scoring 21 points and gaining 291 yards in the first half. The 49ers added just three points and 99 yards in the final two quarters.

Mostert had 65 yards on 17 carries. He has 303 yards this season and averages 5.9 yards a carry. Mostert also has 150 receiving yards and averages 13.6 yards per catch.

Hasty gets chance: The 49ers finished the game with two healthy running backs, Jerick McKinnon and undrafted rookie Ja Mycal Hasty, who had two rushes in his career before Sunday.

Hasty took every handoff in the final 15 minutes and responded with 37 yards on nine tries. His first carry went for 9 yards. And his first carry on the 49ers’ final drive, after the Rams closed to within eight points with 3: 24 left, went for 10.

Hasty, a compact 5foot8 and 210 pounds, showed the quickness and decisiveness he flashed throughout training camp.

“It was the perfect time to change the pace and bring in a fresh guy,” Shanahan said. “And he was the guy we had left and he came in and was ready for the occasion. He’s looked good in practice … so we didn’t hesitate to put him in there. When he came in, he gave us a little bit of a spark and helped us out.”

Running back Jeff Wilson might return against the Patriots after he was sidelined with a calf injury against the Rams.

Shanahan said running back Tevin Coleman ( knee) was unlikely to be activated from injured reserve this week.

New man in middle: Garland will be replaced in the starting lineup by Hroniss Grasu, 29, a sixyear veteran who started the season opener when Garland was out with an ankle injury. Grasu has made 14 career starts.

Garland had replaced Weston Richburg, who suffered a torn patella tendon in December. Shanahan revealed Monday that Richburg also had offseason shoulder surgery and won’t play until at least Week 12.

“The shoulder surgery really set him back,” Shanahan said. “I’m not sure which ( injury) has set him back ( the most) right now.”