Manager Martinez looks to strengthen all three areas of the team, but the stats say the defence is the area that needs to improve.
Everton were stunned at home today by Sunderland, who scored twice on deflected goals to beat the Toffees, 0-2.
Tim Howard is fully fit according to Roberto Martinez and one would expect for the veteran to reclaim his spot back straight away, but with an away match against Chelsea on the docket, there is no reason to invest in him yet.
Everton goalkeeper Tim Howard is expected to miss five to six weeks with a calf injury.
American goalkeeper Tim Howard suffered an injury during the team's Boxing Day match against Stoke and was replaced at halftime.
Tim Howard has improved after an extremely rough start to the season.
Tim Howard put in a historic performance for the US Men's National Team in a close 2-1 loss to Belgium.
The United States lost 0-1 to Germany but escape the Group of Death on goal difference thanks to Portugal's win over Ghana.
USA XI: Howard; Johnson, Gonzalez, Besler, Beasley; Beckerman, Jones; Zusi, Bradley, Davis; Dempsey
Tim Howard, Brad Guzan, Geoff Cameron and Jozy Altidore will comprise the Premier League contingent on the US Men's National Team this summer in Brazil.
Everton have signed goalkeeper, Tim Howard, for an additional two years. The US shot-stopper will now be at the club through 2017.
Chelsea scored the game's only goal in added time, when a free kick landed in front of Tim Howard and the US international deflected it in, slapping him with an own goal in a tough 1-0 defeat for Everton.
Tim Howard kept his ninth clean sheet of the season and goals were provided by Gareth Barry and Kevin Mirallas as Everton moved to fourth in the table with an easy 2-0 win over Norwich City.
Tim Howard was sent off with a straight red card after a challenge on Sunderland's Sung-Yueng Ki and will miss the next Premier League game barring a potential appeal.