Ryder, who kicked three goals in the Bombers' 39-point win over Melbourne in Thursday night's NAB Cup qualifying final, said the pair's ability to impact the opposition ball carrier was crucial in the club's new defence-orientated game plan.
He singled out Jetta, who collected 21 disposals against the Demons.
""The new blokes have stepped up and are doing well, but Leroy, though he's not such a new player, I've liked the way he's played so far this pre-season,"" Ryder said.
""He puts a lot of pressure on the contest and ball carrier which is very important.""
Ryder also said former Hawk Williams, who dropped five kilograms over summer in a bid to resurrect his career at Windy Hill, needed to continue to show the same intensity that he did against Melbourne.
""Over the pre-season he's worked on a few things so that he can be in the side, and he showed tonight that when he puts his head over the ball it really helps the team,"" said Ryder, now 22 and into his sixth AFL season.
Against the Demons, Williams, who played only four matches last year due to a persistent foot injury, delivered the ball beautifully but also attacked it with tenacity, showing he would be an important foil for taller targets Michael Hurley and Scott Gumbleton this year.
With first-choice ruckman David Hille likely to sit out the rest of the NAB Cup as he returns from a knee injury, Ryder said there was no set plan for how much time he would spend rotating between full-forward and ruck in the home and away season.
""At the moment nothing is set out, but it's just a matter of where the coach needs me at the time, be it in the ruck or up forward. I'm happy playing the role between both positions,"" he said.
Ryder said that Essendon,. having progressed to the NAB Cup semi-finals, would not look too far ahead, focusing on continuing to implement its refreshed game plan.
""We're all just about improvement and we've improved a lot from last year through the pre-season, and in the first couple of games we've shown good signs of becoming a better side this year,"" he said.
""We'll go back and have a look at all the vision and pick out all the good stuff, and also look at some of the things we didn't do as well. As long as we don't go away from our roles out on the ground then the coaches will be happy with that.""