One of the major criticisms of Chelsea's summer was the lack of major signings during the transfer window. While the club added several bench pieces to the group, overall, Jose Mourinho was left with basically the same shallow squad as last season. Pedro aside, none of the new additions seemed likely to even sniff a starting role. Given the terrible start to the season and the rumblings about major squad overhauls coming in 2016, Chelsea could be looking to make a few waves this January.
According to the Evening Standard, Chelsea are looking to fight against Manchester City and Juventus for Real Madrid midfielder Isco during the January transfer window. Isco has only started 9 league matches this season under Rafael Benítez's guidance, and although Madrid might be reluctant to sell a player in the middle of a season, the player's worries about missing the Euros this summer might be enough for him to push for a move out of Spain.
Another Chelsea transfer target is Shakhtar Donetsk attacking midfielder Alex Teixeira, whom the Blues are believed to be in advanced talks over a move to London in the near future. But given Shakhtar's reluctance over selling him during the winter transfer window, it's unlikely that Chelsea will be able to acquire him in January.
Alex Teixeira and Isco would bring different skills to the table. The former is a dribbling ball-carrier from deep who loves to get into goalscoring positions; the latter more of a creative attacking midfielder, resembling Juan Mata in some ways. Either way, it should be interesting to see whether these rumours will amount to anything concrete*, and if either of the two would be able to dislodge any of our four senior attacking midfielders in the Chelsea pecking order.
*[Ed.'s note: it should be noted that the Isco rumor seems to be stemming from notoriously unreliable Spanish outlet Fichajes, who have linked the player to three or four different clubs just in the last few days and have peddled the Chelsea story since at least the summer.]