Flanker pair Tipuric and Navidi are both recovering from concussion and continue to go through the normal return-to-play protocols.
Tipuric suffered a heavy head knock captaining Wales to an 18-0 win over Georgia last Saturday.
Skills coach Jenkins said: “Justin is going through his protocols as you normally would after a head injury. We will see how he goes later on in the week.
“He’s in and around and he’s looking OK to be fair to him. It was a pretty heavy knock on Saturday, but he seems pretty good and we will see how he goes for the rest of the week.
“It is a blow to lose Ross Moriarty. He picked up an injury in training. We were hoping he was going to OK for the latter games, but sadly that’s not to be the case.
“If Josh is right, he’s a fantastic player. We are pretty blessed in the back-row area and Josh fits into that.
“For me, he’s a world-class player and the type of guy that can step up and play Test match football with minimal rugby. He is another one we are keeping a close eye on.”
Looking ahead to the challenge of facing England, Jenkins knows Eddie Jones’ side will be a fearsome challenge in Llanelli.
“England are very strong,” said the former outside-half.
“Their defence and work rate is incredible. There are going to be a lot of things we’ll have to deal with on Saturday and we’ll have to do them well otherwise we’ll come unstuck.
“There is no doubting that, but I’d like to think we’ll be more than ready on Saturday to match and hopefully better England in a lot of areas. We’re certainly going to go about it that way.
“We wouldn’t see it as a shock if we won, but I’m sure the rest of the world would.”
Wales are hopeful No 8 Taulupe Faletau will also be available to face England after recovering from a slight knee injury.
“It’s a huge game for us. We want to win every game we play,” said Jenkins.
“I’m used to being successful and expecting to win at home. I don’t see any it being any different on Saturday.
“We know it’s going to be tough and we understand what’s in front of us, but we have got more than a chance on Saturday.
“We need to be right on the edge and right on the money to give ourselves a chance. It would be a huge boost to everyone here and to the country to win.”
