There were fears that Semenyo had suffered a serious injury after he was stretchered off in the recent 3-0 win over Brighton & Hove Albion.
Speaking after the game, Iraola told reporters that he was concerned that Semenyo had suffered a "bad" knee injury against the Seagulls.
However, the Bournemouth boss has now revealed that Semenyo has avoided serious injury and should be available for Saturday's trip to the Emirates Stadium.
Semenyo declared fit for Arsenal fixture
"I was surprised as the next day he woke up, he was feeling better," Iraola told reporters at Friday's press conference.
"The knee was not so swollen, we could have some hope with him. There is news this week that the MRI has been clear so Antoine has been doing some things with the team this week.
"The medical staff were optimistic but until you get the confirmation you don't know. Everyone was not even delighted after Sunday, Antoine is an important player for us, a very good character, everyone loves him; this is very good news for us.
"He's going to be involved in the squad and this is the best news for us this week. It looked bad but he's so strong, his strong muscles keep his structure in place and everything has been cleared, he's ready to travel with us and be part of the squad."
The Ghana international has featured in 30 Premier League matches this season, scoring eight goals and providing two assists.
Zabarnyi set to return
Ukrainian defender lllia Zabarnyi will be available for selection after missing the comfortable win over Brighton due to illness.
The midfield duo of Philip Billing and Romain Faivre have both been passed fit having recovered from illness and injury respectively.
However, Iraola is still unable to call upon Chris Mepham, Ryan Fredericks, Milos Kerkez, Tyler Adams, Marcus Tavernier and Luis Sinisterra.
The 10th-placed side will head into Saturday's fixture with hopes of claiming their first-ever Premier League away win over Arsenal.