(Reuters) – Chelsea forward Christian Pulisic has stepped up his recovery from an adductor injury but Monday’s Premier League game against Manchester United comes too soon for the American, manager Frank Lampard said on Friday. Pulisic has not played since the 1-1 draw at Brighton & Hove Albion on New Year’s Day. Striker Tammy Abraham (ankle) will be assessed before the game while midfielder Ruben Loftus-Cheek (Achilles) is close to returning. “Christian trained with the under-23s today, so won’t be fit. Ruben won’t be fit for this game… he’s getting closer… it’s great to have him nearly back,” Lampard told reporters. “Tammy’s still feeling the effects. He trained today… we’re hopeful but he’s to be assessed over the weekend.” Lampard earlier said winger Hakim Ziyech will add the spark that has gone missing from their midfield after the club agreed to sign the Morocco international from Ajax Amsterdam. The 26-year-old will join the Premier League team in the close season after the two clubs agreed an initial deal for 40 million euros ($43.36 million) on Thursday. “He’s certainly a player we hope can bring that bit of creativity,” Lampard said. “He scores goals, assists… he’s got a great left foot and plays generally off the right side but can play behind the front man. Probably when you look at us this season, there have been game where we may have maybe struggled to unlock the door.” Chelsea, who successfully appealed a one-year transfer ban, did not sign any recruits in January and Lampard was asked if more arrivals were expected at Stamford Bridge. Veteran wingers Pedro and Willian are out of contract at the end of the season. “I don’t know. We’ve to worry first about where we’re at,” added Lampard, whose side are fourth in the standings on 41 points. “Trying to come in the top four is the priority for us so my main concern is that. But we’re always on the lookout and we’re always working together to see how we can improve.