Former Bradford Bulls star McKenna hobbled out of the Keighley game last month with a hamstring strain and has not yet fully recovered.
But coach Ellery Hanley should otherwise have a full squad to choose from as the Dons look to earn their seventh straight National League Two victory.

Assistant coach Tony Miller said: "Chris is not fit enough to return this week but hopefully he'll be back next week.

"He is still not 100 per cent.

"Initially we thought the Workington game would be on Sunday but now it's been moved forward it has given him less recovery time.

"It's not worth risking him - we want to make sure he's right for the rest of the season."

Fellow centre Zeb Luisi, who has suffered medial ligament knee damage, is touch and go for the trip to Cumbria, while utility back Shaun Leaf trained this week and is back in contention after missing the last two games.

No game last weekend - due to Barrow's involvement in the Challenge Cup - meant the Dons enjoyed a rare break but it allowed Keighley to leapfrog them into top spot.

Now the players are chomping at the bit to return to action and regain pole position in NL2 - at least until Keighley visit York on Sunday.
Miller said: "We trained Friday and then Monday so the players had the whole weekend off.

"They've played a lot of rugby so it was a good opportunity for them to recharge their batteries.

"When they came back the team spirit was excellent, they are all upbeat and cannot wait to get back out there on Friday.

"As long as we keep winning then the league table will take care of itself."

On the flip side Workington were also without a game last week and it was a particularly welcome break for them after suffering a 66-6 thrashing at local rivals Barrow in their previous outing.

The 13-try mauling was their sixth loss in seven NL2 games, although the fourth-bottom side have acquitted themselves much better in their other defeats having picked up four losing bonus points.

Like Doncaster they will be aiming to return refreshed tomorrow night.
Miller said: "They had the week off as well and they got hammered the last time they played so their coach will want a big response from them.

"They have got a massive pack - although it is not as mobile as ours - but they do a lot straight off the ruck.

"It's never easy up at Workington but we will go there with the right attitude and hope to build on what has been a great start to the season."