The club admitted two discount policies, in place last season, were inadvertently dropped during the summer but have acted immediately to rectify the issue.
A discount policy for non-corporate adult season-ticket holders, who buy all three home games in the Champions' League, is another policy to be reintroduced.
Less than 30,000 attended Chelsea's opening Champions' League game against Anderlecht, and Kenyon said: "A major issue recently, both at Chelsea, and in football generally, has been ticket prices and the effect this has, or could have, on attendances."
The two policies rectified by the club mean a 50 per cent discount on full adult prices for juvenile and OAP season-ticket holders (not in the Family Section), for Champions' League games.
Kenyon will issue an apology to fans over the pricing mix-up in the match day programme for today's game with Aston Villa.
"On these two issues the board has to make a straightforward apology to our fans. These were overlooked in the recent overhaul of our ticketing policy," Kenyon said. "Clearly it is incorrect for a juvenile, in say the Matthew Harding Stand, to pay full adult price for Champions' League games when he or she has a discounted season ticket.
"All juvenile/OAP season ticket holders will be contacted in the future and given a 50 per cent refund for the Anderlecht and/or Real Betis games."
Tickets for Chelsea's Champions' League match with Liverpool will be priced at the discounted cost.