Henderson has been missing since New Year's Eve with a heel injury, while Matip has been sidelined for seven games after sustaining ankle ligament damage last month.
However, the pair returned to training yesterday alongside Philippe Coutinho, who made his own comeback from injury during the EFL Cup semi-final defeat to Southampton on Wednesday, and Klopp will now wait to see whether they will be available for the trip to Old Trafford.
"They all were in training yesterday, so [we have] to wait on how they reacted to the training yesterday then we have to make decisions. The last game was only two days ago and so we have to wait for the reaction of those players too and then we make a lineup. But of course they are much closer than they were before any other game in the last few weeks so that's good," he told reporters.
"When Phil is not playing, of course you miss his creativity and finishing and all that stuff. He's a very important player for us, it's the same as Hendo in a different role. When they are not available then I actually don't think too much about them because you have to find other solutions.
"That's what we did pretty good in the past few weeks, especially when we had to play without Phil. Of course it needed a little time adapt to the new situation because he has a specific kind of play in how he interprets his role as an offensive midfielder, defending most of the time on the left side. That's how it is. But, [it's] good that they are back, if they are back."
Liverpool are winless in the three matches they have played since Henderson picked up his injury.