I've seen Gomes have more control over games far more than I have Sigurdsson. Sigurdsson has scored a few goals, that's it. Without his goals, he is absolutely useless and a complete passenger. As seen now since he stopped scoring. His performances really haven't changed much besides.
Last year, away to Arsenal, Gomes came on, his 1st game back, and looked the best player on the pitch for 30 mins. Afterwards, Ancelotti said he was ready to play more, but Gomes said he wasn't, and this sums up his problem. It's all mental with him. Which is not a particularly good sign, to be so fragile. But at the same time, if we can get him confident and to stop playing within himself, we would have a fine player. It's a tough one.
There were signs before his injury earlier this season that he was starting to feel his way back in to games, and there were signs again on Saturday. But it needs to be more than just flashes, and for longer than 20 minute spells. I'd say he's worth sticking with till the summer, and see if he can find the form he is capable of, and if not, sell him back to Spain or Portugal and go for an upgrade.
On the other hand, i'd sell Sigurdsson tomorrow just to get his stink out the team. Anyone from U23s would offer what he does but with 100% more enthusiasm and fight. The only reason I can think of for him still being around is that we are hoping that by being involved in the number of games he has, it will convince another team that he's worth a shot. I've wracked my brain and can think of no other explanation.