100% yes. I think a keeper is just as important as a reliable forward. With a quality a keeper I think our defenders would have more confidence in him, then the midfield should be more confident in the back four etc.
A long term centre half should be next though, as by the end of this season we could be left with 1.Stones (class but still young) 2.Jagielka(Almost 33 and deteriorating quickly) 3.Browning? 4.Galloway? So a centre back of around 22/26 who can slot straight in with Stones would be ideal, perhaps Schar, Virgil van Dijk or Nastasic?
Another winger as at present we have one quality (Mirallas), one inconsistent (McGeady), one aging (Pienaar) and one absolutely jarg (Atsu). So without another class winger we can't really play two men wide without having somebody out of position.
Finally a No.10 would allow Barkley to drop back but would then also mean we are further clogging up an already bloated central midfield.
Martinez definitely has some decisions to make.