The 24-year-old started four of Howe’s opening six games in charge before picking up a hamstring injury in December against Liverpool.
Then, an ongoing groin problem - which required surgery in March - contributed to Lewis being left out of United’s 25-man Premier League squad for the second half of last season.
Lewis was set to be handed a chance to impress in pre-season and win back his place in Howe’s squad, however, the former Norwich City full-back has not played a single minute due to a calf issue.
What the short-term future holds for Lewis remains unclear but Howe insists he “believes” in the player.
Howe said: “Jamal, we hope, can stay fit and show us what he’s capable of. I believe in him as a player but he’s just had really bad luck.
“He’s got a lot to offer physically, we’ve certainly seen that in pre-season - an incredible athlete.
“He needs consistency of training at the moment that he needs, and hopefully he can get that.”
Time is running out for Lewis to make an impression this summer with no return date mentioned.
Indeed, one avenue Howe could explore is loaning the left-back out for the season and then reassess his future next pre-season.
That way, Lewis can put his injury problems behind him and return next summer in peak condition.