Roberts returned from a one-month absence as a late substitute in last weekend’s epic 5-4 victory at Birmingham City but failed to make the bench for the New Year’s Day clash at West Brom.
The 20-year-old was reportedly suffering from a tight hamstring and left out as a precaution with Bielsa not wanting to take any chances over a player he feels could be very important in United’s Championship run-in.
Leeds have lost the services of two of this season’s loanees with striker Eddie Nketiah recalled by Arsenal and winger Jack Clarke heading back to Tottenham Hotspur, both over a lack of game time.
Bielsa said in the aftermath of the 1-1 draw at West Brom that he would now analyse the situation in regards to bringing in replacements.
Either way, the Whites head coach has provided a strong indication as to the value of Roberts who Bielsa sees as an option either as a centre-forward, winger or a no 10 in the absence of Pablo Hernandez.
Spanish playmaker Hernandez injured his hamstring in just the second minute of the 2-1 loss at Fulham four days before Christmas with the 34-year-old facing a month out.
Asked about the whereabouts of Roberts for the West Brom clash, Bielsa said: “He didn’t feel 100 per cent recovered from the problem in his leg.
“Maybe he could have participated, but we didn’t want to take this risk.
“We think he’s a choice at centre-forward and also as playmaker.
“He can play as a winger too. We are going to miss Pablo, Clarke, Nketiah, so we want to protect him.”
United - who sit top of top of the Championship - are back in action on Monday evening with a clash at Premier League big guns Arsenal in the FA Cup third round.
Bielsa will hold his pre-match press conference on Saturday (12.30pm) where the head coach is expected to give fitness updates on his injured players.
As well as Roberts and Hernandez, Jamie Shackleton recently returned to training after a hamstring issue but the midfielder played no part in any of United’s Festive fixtures.
Fellow midfielder Adam Forshaw also remains sidelined with a hip issue.
Leeds then return to Championship action next Saturday when former Whites boss Garry Monk’s eighth-placed Sheffield Wednesday side visit Elland Road.
United and second-placed West Brom hold a nine-point advantage in the division’s automatic promotion places with Brentford third although fourth-placed Nottingham Forest would move third and six points behind the top two if winning their game in hand at home to Reading.