Morgan, who spent a spell with the U's earlier this season, has not featured since March 19, while McClure missed the 1-0 victory at Morecambe last time out.
Both are close to a comeback but it is unclear whether they will make it in time for Saturday's clash at the Kassam.
Matt Spring looks set to keep his place in the starting line-up having come through 90 minutes in his first appearance since February.
Matt Ingram, 19, will continue in goal in the second of three successive away games, having made his first two senior appearances over the Easter weekend.
- Sports & Recreation