Welsh defender Matthews was subbed out of the Bhoysâ€™ 3-1 win at Heart of Midlothian on Saturday after injuring his ankle whilst young winger Forrest has an ongoing back problem but Lennon hopes both are fit for Wednesday nightâ€™s first group match.
"Adam is fine. He just jarred his ankle and couldn't continue but we are hoping he will be okay for Wednesday. It is just a twist,â€ť said Lennon.
"James Forrest, with his sciatica problem, we are hoping he will be okay to travel and be fit and available.
"Thankfully, apart from that, we have a clean bill of health.
"The only loss, and it was a big one, was Steven Mouyokolo with an Achilles injury during the week."