According to pro football reference, Mitchell started in 6 games that year due to the injury situations of other WRs.
In those 6 games:
2 catches for 33 yards
2 catches for 7 yards
4 catches for 98 yards *
8 catches for 82 yards *
1 catch for 14 yards
3 catches for 29 yards
*Two of three of his best games, the other being the SB comeback (6 catches for 70 yards).
In 4/6 starts, he had 33 yards or less. The legend of Malcolm Mitchell has grown due to coming up big in the comeback, particularly on one drive where he had a few clutch catches.