Ekstrand was forced off late on in last weekend's 2-1 win over Bolton nursing a knee injury and remains a doubt, with a decision due to be made as late as possible.
Nosworthy replaced Ekstrand for the closing stages but he has been on international duty with Jamaica this week and the lengthy travelling may have taken its toll ahead of his late return to Hertfordshire.
Boss Gianfranco Zola could have a ready-made replacement at hand in the shape of Tommie Hoban, who stepped up his fitness after an Achilles injury by representing the Republic of Ireland Under-19s in midweek.
Midfielder Ikechi Anya (hamstring) and defender Neuton (back) remain out.
