England left-back Baines and Costa Rican midfielder Oviedo missed the end of last season.
Baines required ankle surgery after suffering a recurrence of an old problem in a game against Sunderland in May while Oviedo broke a metatarsal in training in April.
The duo have both been included in the Toffees squad for the upcoming pre-season trip to Scotland, which features friendlies against Hearts on Sunday and Dundee next Tuesday.
Martinez told the club's website, www.everton.tv: "We have got some very exciting news with Bryan Oviedo and Leighton Baines joining the group for Scotland.
"They are raring to go as you can imagine
They are two pristine professionals and they are a similar profile of player, so they have been helping each other with their work
They are full of energy and desperate to join the group."
New signing Gerard Deulofeu, who has joined the club on a permanent deal from Barcelona after a successful loan in 2013-14, is not travelling.
Deulofeu suffered a hamstring injury against Arsenal in the Asia Trophy in Singapore but should be fit for the start of the season.
Martinez said: "It's not a real concern, it's an injury that I don't think will stop him starting the league campaign.
"His physicality is that he is a sprinter and we need to make sure he is fully recovered before he is back on the pitch."
Source : PA
Source: PA